Representative set up my account incorrectly

I have had the ATT Home Internet Fiber plan (300 Mbps) since May of 2022. I saw the current promotional offer of a 25% discount on ulimited wireless plans for current ATT fiber customers setting up new wireless lines, plus an additional $200 in bill credits per line ($10/mo for 20 months) when you buy a new phone and trade in your old phone.

On March 10, 2023, I went to an ATT store and opened two new lines of the unlimited premium plan and ported in our numbers, purchased two new S23 Ultra 256gb to be financed, along with two phones to trade in to receive the $800 trade-in credit per device. I told the representative specifically about the bundle deal mentioned above, and was assured that I would receive it. Well upon looking at my accountthr next day, I noticed he opened another, separate account for the wireless service rather than add it to my current fiber account.

When I went back to the store 2 days later to ask his co-worker about this, I was told that I was NOT eligible for the aforementioned bundle discount because he opened a new separate account rather than bundle the accounts together.

Confused, I called ATT customer service 3 separate times, and two of the three agents assured me that I will be getting the discount, with the third seemingly unsure. 

My question is, who is telling the truth here? Will I get this discount or not? And if not, is there anything I can do about this representative incorrectly (whether intentionally or accidently) setting up my account? I don't see how it would be fair to me if I do not get the specific discount I requested and was promised.

Another thing: upon reading online, multiple users have said that as long as the billing address is the same for both accounts, the discount should be automatically applied. Is this the case here?

I'm worried because if I don't get this discount, I'll be paying close to $70 more per month than I was expecting. In addition, I only have a 14-day window (as told by the in-store representative) to return the devices, but the call center representatives said it could take anywhere from one to three billing cycles for the credits to be applied.