ATT only cancelled my Uverse and kept billing me for land line

I ordered both services through the same service agent. We moved over to Xfinity in February 2017 and I called AT&T to cancel service. They cancelled the U-Verse but kept billing me for the land line. I never received a bill or notification, only a monthly deduction from our Bank account. Last month my ATM card was stolen so I had to change the account. Then I received a notice of cancellation from AT&T for an account that I had requested to cancel 13 months ago. When I called CS, I spent 45 minutes navigating the Org until I got to Jessica with Customer Loyalty. She was very nice and informed me that they are two separate businesses and that they didn't cancel the Land Line. I asked to have the account cancelled and my bank account credited for the wrongful charges. I was told they could only go back 60 days. The justification was that they were separate businesses. Separate businesses serviced by the same Customer Service Group and Sales Organization. I asked to speak to a supervisor and was told someone would have to call me back. I'm not holding my breath so I will share this story in the hopes that they will do the right thing.