Still have money taken from checking for cancelled service

Why is ATT still taking money from me when I cancelled direct TV in May? I was a 15 year loyal customer who retired and moved. They sent me a box and I returned the equipment in May. In July, I saw another payment to ATT and called. I called again in August, September and October. Once they told me it was taken care of and I would be refunded. That never happened. Now all they tell me is that they cannot access my account. They said I have two closed accounts, one old direct TV account and an ATT account. Both have 4 digit PINs that I have never set up. One even has a security question that I never set up. With that, they say they cannot help me. One lady said I have to go to an ATT office to change the PIN but that did not work either, both accounts said closed. I called from there, another rep got her supervisor on the phone, he said I will check into this and call you back within one hour. No call back. The last call I made today, another manager, said I have to file a dispute with my bank.  I will tomorrow. But it is so sad that NO ONE from ATT can fix this.  NO ONE.