Being Charged for an account that was closed by AT&T because of duplicate accounts.

My husband was in Costco and a young man representing Direct tv approached if says that he could help us get our monthly bill decreased.  He signed him up for another account, which he put a bogus address on it.  He also had my husband meet another person to pick up equipment.  We were having issues installing the equipment when we found out that we could not have 2 accounts open.  The new account was closed, and we sent the equipment back.  Sent a bill for $224.06 which was told that was for equipment which we had already sent back.  That conversation was over a year ago, so we thought it was resolved.  Now we are getting letters from a collection agency.  

I called to talk to Direct Tv and was told that since the account had been sent to collections all the notes from previous conversations had been deleted.  The only notes she had was that it was written off 7/29/21, reentered 12/2021 and then sent to collections on 6/17/22.  We have had an account with Direct tv for many years.  

I am hoping that someone will see this and help me resolve this situation. 

Judy or Robert  [EDITED per Community Guidelines]