Billing Dispute - DirecTV

This question is about "Billing Dispute", with DirecTV channels, programming, equipment, and sports. Unfortunately I have a major issue that I haven't been able to get an acceptable, or viable, relsoution. I cancelled my Uverse service in April 2015, yes over 1 year ago. I have recently been contacted by a collection service for Uverse telling me I owe over $500 for non-returned equipment. Speaking with Uverse collections this morning I was informed the equipment had indeed been return yet I was charged for April, May, & June service. Granted I cancelled my service the middle of the month and followed up in 4/30 with a call telling the Uverse team my Charter internet had been installed yet I hadn't received anything from Uverse regaurding my cancellation.The collection agent told me this WAS in ERROR. I was transfered to billing but was not connected. Later on I called with the agents name & spoke with another agent who then informed me that I was resposible for the charges since I never cancelled my services. Yet she said and I quote "I see where you called in to verify your cancellation but you said you would have to call back.". OK if I state the word CANCEL MY SERVICE I shouldn't have to call back in. Nonetheless we continued for another 5 mins or so & I asked to speak to her supervisor. 10 minutes late I am told the supervisor agrees with her. I then either asked to speak to the supervisor or the supervisor's manager inwhich I was disconnected. I then issued a complaint via the FB page. Again I am getting the same answers. Also I was told that there was some how a PPV movie charged to my account in May! When our equipment wasn't even hooked up. I am not sure where else to turn. The customer isn't always right I completely understand that but this time the customer isn't a Uverse customer any longer inwhich I am no longer viewed as an important client. Does anyone here have any idea as to who to elevate this concern to? I agree I will pay for my prorated portion of the bill for April 2015 but May & June are completely out of question. Any help would be greatly appreciated.

This topic covered Billing Dispute, and DirecTV satellite tv service.