Worst experience ever. [Edited]

Xfinity sent me a phone that I never took possession of, as I was not physically present to sign for the phone, the currier (UPS) returned it to sender. The phone never made it back to xfinity, but as it is between xfinity and UPS, not anything I can do. Xfinity still charges me for the phone that I never received and charges me monthly for a phone payment/extra line that I never received. I have spent at least 40 hours talking to at least 15 agents, supervisors included, and they continue to find excuses to keep charging me, despite clear indication from tracking that I never took possession of the phone. They also promised a $500 credit with my trade in that they initially lied about not receiving (I have tracking to prove they did), then told me I had to upload my old cell phone bill from T mobile to receive the credit; T mobile can no longer send me statements as I am no longer their customer. One supervisor told me I need to file a police report for the lost phone, despite my explaining to him many times that I never took possession of the phone and that’s not my responsibility to file a police report. He was extremely snarky and tried to tell me “it’s the law that I file the police report”. When I asked his name he told me a made up name “[Edited: "Personal Information"]” and when I told him I would escalate this issue as he was very wrong in every way, he told me he was the supervisor and there was nothing I can do about it. The incompetence and absurdity of this situation and Comcast’s so called customer service is mind blowing, not to mention the at least a dozen times that I waited for over an hour and was hung up on and had to start over; or when I was promised to be transferred to the supervisor after waiting for 1 hour + to be transferred to a completely wrong department like tech support.