Switch To Another Carrier

I have over 50 emails, countless calls, and probably 20 store visits invested trying to simply shut down an old account which was supposed to be shut down in June of 2022!  I was a business partner with my now ex wife and the only way they could take her off of it was to shut down the old account (they said) and move all my devices to the new account.  So that's what we did, but one device didn't move over and I continued to be auto drafted for the monthly service. I also cannot access that account because my login information only works for the new account.  Following me?  Fast forward to March of 2023 and it is still not done.  So, I go and cancel the credit card associated with that old account.  I have been getting billed for $130 and some change for months and they tell me that "we have put in a request for that money to be credited to your account, but there's no guarantee."  Are you kidding me AT&T?!  Also, get this, there is this mystery I pad that showed up on my new account (I've never owned and I Pad) at the same time that the old account was supposed to be closed and the new one opened. Guess what?  It is still on my new account and I've been getting charged $20 a month for it for months!  Nobody can seem to figure out how to get it off!  There is no reason why this has to be this hard.  My question is....recommendations for a new business carrier who takes care of their customers and has good coverage.