Adding a device, resolving an outstanding balance with 2 week resolution time?

Cross-posting from the DirecTV forums as well,

I went to add a tablet to our AT&T account tonight, and was informed that there was an outstanding balance of approximately $180 from 2020 from a Uverse account (which we've never had, but we did have DirecTV). Following up with a phone call, after a 93 minute phone call where I was bounced around to at least 4 different people, I was told that they could see I'd returned the DirecTV equipment (I don't have the exact date I sent it back, as I think I lost the UPS receipt), but that they still didn't have it on their end, and that they'd look into it further, but that it'd take 2 weeks for the issue to be resolved. When I asked for clarification, she said that it didn't even mean that the charges would be dropped, just that they'd have an answer in two weeks.

I'm aware that you supposedly can't add more devices to a plan when there's other outstanding balances on other AT&T companies,  but we just added my father in law's cell phone to our plan within the past year, so clearly it wasn't an issue then. I have zero intention of paying on something that is out of my control, and has been for some time, but at this point it seems like they have me over a barrel, either wait 2 weeks for someone to figure out the incompetence (which I have no faith in even getting a call or email back) or just pay the money so I can get this tablet added and move on...frustrating and an absolutely god awful system.