Worst Tech Support I have ever had. Even worse than Virgin Mobile.

Tech support can run through the usual options because you asked them to, but cannot create a network for you in an area with poor coverage.  It’s up to you to select a network that works.  

Your expectations for what tech support is able to do is unrealistic. Perhaps ATT just isn’t the right carrier for you but that 6 year old phone model might also be the reason.

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@ctdm456 wrote:
My phone is only 3 years old but I know the IPhone 5s has been around longer than that. By the way, other folks sitting next to me use the IPhone 5s with AT&T and they have no problems whatsoever. So, saying that it's my phone seems unreasonable. Actually, I’d say quite the opposite. If other prepaid users with the same phone on ATT have no problem, that definitely suggests it’s your phone. Maybe not your phone model since other 5s’s work, but your specific phone. However, if those other users are postpaid, that’s a different story.
Why do I have service at my home and other places but not in the high tech mecca of downtown Austin TX?
My expectations are simple, I need my phone to work when I am at my workplace. Are you saying that is an unrealistic expectation, to ask for help? No, I’m saying your expectations for what customer support is able to do are unrealistic. They aren’t able to touch the network. Those basic troubleshooting steps they have you do is all that they can do. If you think that is poor customer support, so be it but there is only so much they can do.
It's my perception that something is going on differently with AT&T Prepaid vs. AT&T Wireless at the downtown Austin TX Tower(s). I know that Tech Support probably wouldn't know that but they should at least have the means to ask that question to the right people. Fair point. Prepaid does get less coverage than postpaid. More than likely those postpaid users are able to use a tower that prepaid users can’t. 
I do agree that AT&T is not the carrier for me. There are other reasons for disliking AT&T but this is strike 3 and out.

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@ctdm456 wrote:
At my workplace, my phone shows 4 bars AT&T LTE or 4G. People sitting around me have the same signal strength with AT&T and can make and receive voice calls. I get a Call Failed every time I try to make a call. But, when I leave work and go home, I have 1 or 2 bars AT&T LTE and can make all the calls I want with no problem at all.

Not sure how many times I need to power my phone off and back on or Reset Network Settings or remove and re-insert the SIM Card.
And why tell me someone is going to call and I make arrangements to get that call, yet no one calls. 

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Here’s what I think the problem is, and why you have to start shopping for a new phone:

Carriers are shutting down 3g services and requiring phones that work over LTE only.  Your phone is picking up a strong LTE signal, but 3g is poor.   Your phone is unable to make calls over LTE because it’s too old.  You are able to get a good 3g signal at home and do calls go through over the 3g network.  

    You can turn off LTE on the phone in settings at work, and you should be able to make calls.  

@ctdm456   BTW, It’s very unlikely other users have a 5s.  I haven’t seen one in years.  The SE is exactly the same, even fits the 5s case, but is much newer and has the correct hardware and software to use Voice over LTE.  And users often misidentify it as a 5SE.  

Problem Solved....  Changed carriers and suddenly, my phone is working again at my workplace. Same signal strength as AT&T (4 bars LTE) but now I can make and receive calls from my desk at work. BTW, I changed to T-Mobile, so no, it's not my phone as has been suggested. AT&T has done something with their downtown Austin, TX Towers. Excellent way to lose customers AT&T.

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@ctdm456 wrote:

Problem Solved....  Changed carriers and suddenly, my phone is working again at my workplace. Same signal strength as AT&T (4 bars LTE) but now I can make and receive calls from my desk at work. BTW, I changed to T-Mobile, so no, it's not my phone as has been suggested. AT&T has done something with their downtown Austin, TX Towers. Excellent way to lose customers AT&T.

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 If you want to look at that way fine.  🤔.   

But the fact that T- mobile is a couple  years behind AT&T and not yet shutting down their 3G network, and still has a 2G network might have a whole lot more to do with it.   AT&T is progressing toward 5G. Your phone cannot work on an LTE only network.  It’s days are numbered.   AT&T is already actively shutting down its 3G network. It is certainly going to be shut down in locations where It is actively being repurposed for 5g.  Like major cities.