Xfinity Mobile Billing Concern

I received an email stating that my past due balance needs to be paid to prevent disconnection. I switched from Xfinity mobile over the summer as I was planning to move to an area that did not have Xfinity cable and mobile service.

I have multiple recordings from different representatives who advised that I did not have an account any longer, and had no balances due. I advised the first representative that I spoke with in the string of contact that I needed this last bill by a certain date for my new carrier to pay off my old bill and devices. I expressed the importance and confirmed multiple times that there was no remaining balance. I was later told that AT&T paid off my account. I called multiple times and confirmed this with multiple people because I did not want to get stuck with this bill after the fact when I needed the final bill for it to be paid off months ago by AT&T.  I should not be held responsible when I did my due diligence, attempting to obtain this last bill for my new carrier to pay off the balance.