Unable to unmerge AT&T/Yahoo account. Cannot log into Yahoo.

The following is long, but it explains all the details about my issues with not being able to access my Yahoo email accounts.  I'm posting this in as many places as possible, in both the AT&T & Yahoo Forums in the hopes that someone will have a response that will be acceptable and help get the problem fixed. The bottom line:  I deleted my main email account from AT&T (as stated on the AT&T website was the thing to do), but now I can't access them through Yahoo because I keep getting routed back to the AT&T site to login, which doesn't work.  Neither AT&T nor Yahoo seem to be able to help me.  At least AT&T tech support can be called and we can and speak to someone, but this is not at all possible at Yahoo.  I'm beside myself with this and would like to hear from anyone else who has encountered this problem and hopefully got a resolution.

I have 3 Yahoo accounts (main and 2 sub accounts) that I have had for years and were associated with my AT&T account. I was having trouble with mail performance on my native iPhone & iPad apps after upgrading to iOS 11, and one of the solutions I found online to fix the problem was to delete the email accounts and re-add them. I deleted all 3 from my iPhone, but then could only add back the main account (not the 2 sub accounts). It wasn't a password issue, and every thing I tried only led me back to the AT&T site. Then in the Yahoo forums I stumbled upon the need to unmerge my Yahoo mail accounts from my AT&T account. Made sense to me, so I did more research to see what this was all about, and found some rather detailed instructions on the AT&T site (that I got to from a link that was in more than one Yahoo forum post) that I needed to delete my mail account/Account ID (the main one, which would also delete the sub accounts) with AT&T, then login to my Yahoo mail accounts and unmerge them from the AT&T account. This also made sense. So I got into the old AT&T account and clicked on "delete" next to the main account. This is when my real problems started because now I can't get back into any of my 3 Yahoo accounts from anywhere to even get to unmerge them from AT&T - no matter what I do I get sent back to an AT&T page, and AT&T doesn't recognize anything about me or my accounts (which was also the case before I "deleted" my mail account ID from AT&T). By deleting my main account from AT&T, I'm locked out of my 3 Yahoo accounts on my desktop, iPhone and iPad and am stuck in this vicious circle. If I go to mail.yahoo.com, I see the Yahoo logo in the upper left corner, I type in my main email address, but when I hit "next" to get to the password page, the logo in the upper left corner is the AT&T logo and the Yahoo logo, and nothing is recognized and I have no way of just getting into Yahoo. If I try "forgot password", I also get nowhere, because that sends me back to an AT&T page.  I have called AT&T support twice, and they were nice enough to spend time with me to see if they could help, but they can't because I deleted the email account(s) from them, so it's an issue that needs to be resolved by now unmerging the Yahoo accounts from within the Yahoo accounts. I had to create a new Yahoo account and email just so I could post in the Yahoo forums and so I have a "valid" Yahoo email address that will be recognized by Yahoo.  When I log in to my "new" email account, I can see the old accounts/emails. If I use the Yahoo mail app on my iPhone, I can see the new account and the old accounts and in the settings there are "sliders" that I can suposedly turn "on" if I want to add the 3 old accounts. However, when I turn them on, they can't be accessed. I can still see everything in the 3 old email accounts in the apps on both my iPhone and iPad, frozen in time, with no way to get into them. How can I see them, but can't access them? Don't these reside on a Yahoo server?  In a posting in several Yahoo forums, Yahoo stated that these issues need to start with AT&T and, if AT&T can't resolve the problem, they could escalate to Yahoo. When I called AT&T I was told by one of the support people at AT&T that this is not anything they can do. AT&T apologized and wished me luck.  There seems to be no way to contact Yahoo for help with this - Yahoo's online "help" just leads to articles that don't help, and everything I click on just leads me back to AT&T. I see phone numbers for Yahoo on the Internet, but Yahoo has stated that they have no phone numbers available, and not to call the ones I have seen.

As with most of us nowadays, I rely on my email for so many things (like notification of bills due, to name one of the most important things). I spent the entire day on 12/10 updating my email address on over one hundred sites that are all dependent on the email.  I started with the most critical (such as Financial) and services I pay for, then started to change the email on all the other accounts that are somehow tied to my old email address.  I still have over 100 that I need to update.  Fortunately I have a password manager, so at least I have some way of making sure I get most of them, but I'm sure there are some that I will miss.  Also, the email address on one site is sometimes dependent on the info in another site.  And what about "recovery emails" that are no longer valid?  And some sites send a verification email to the email I don't have access to, so now there's a list of places I need to call to get my email changed.  And let's not get into the Apple ID, which is my "old" email address, and all the downstream effects of changing that.  And my recovery email for anything that happens to my iPhone or iPad is another Yahoo email that I can no longer access.  Then there are all of my contacts that I need to notify (because anything still sent to one of the 3 emails I can't access doesn't bounce back as undeliverable), and all the places where I don't necessarily have an account, but they use my email to notify me (like my doctors and my veterinarian).  I'll never remember all of these.  And I'm looking at having to rebuild my contact list for my desktop version.  Now I'm researching to see how I can export the contacts on my iPhone to import into the Yahoo contacts.  I'm sure there are other things I've not yet thought about or run into yet that will need to be dealt with and fixed.  This whole thing is a nightmare. 

In reading the postings on both the AT&T and Yahoo forums, there are so many of us who have problems and no way to get the help to get them resolved.  Sorry for rambling and if I've repeated myself in places, but as of the date of this posting I've spent more than two full days on this and I'm on the verge of having a breakdown over it. If anyone reading this has had the same problem or can offer any good advice, it would be greatly appreciated!!!

Thanhk you for your long explain the problem with UNMERGE AT&T Yahoo account and you somehow help me to explain that. I had exactly the case like yours and I did exactly what you had done. Still I cannot get to my old Yahoo which merged with AT&T and the free Yahoo account I had. For two days I have to change every single contact I have either by email or phone call.

Thank you @ChristianN_WI! I will definitely try this. It’s the best ray of possible hope I’ve seen!

My early reply was deleted, possibly as a result of my username change. I was referring to this tweet from Yahoo Customer Care, in case other people need help with a similar issue: https://twitter.com/YahooCare/status/940322249743020032

Thank you @ChristianN_WI. My heart sank when the post disappeared. Then I remembered that I have it in the email I received about a new post. I just got home from work a little while ago but will be trying this in a little while.

Out if curiosity, has your problem been resolved and, if it has been, was it because you sent a DM to Yahoo through Twitter, or some other way?

I didn't try separating/unmerging my accounts on my own and haven't had a problem logging in. I've been looking into this issue because AT&T reported to me that they separated my AT&T and Yahoo accounts, but when I log into mail.yahoo.com the site looks the same as it did when my accounts were merged, with links to AT&T services at the top of the page.