I have the same problem, signed up in June for internet and tv service. I picked up the modem and DVR at Comcast service center. However, I did not used or activated the service since of traveling. I called to cancel and was told to bring back the machines to complete the cancellation. My husband returned the modem and the DVR to Comcast service center as was told in August. However, they still sending me bill for accumulating service until now. I know that I still have to pay partial of the bill and want to get an adjustment bill. I had called several times and spend hours of waiting and explaining my situation. I was told because I didn't called to cancel, I have to pay for their service until end of October. (That when they terminated the account for no payment). In the last phone conversation, I asked the agent if Comcast have record when I returned the equipment, she said she does not know but it showed that they don't charged for equipment anymore. I then asked if I don't have Comcast Equipment how do Comcast still charge for service that they did not provide. She yelled at me that if I picked up the equipment I have to pay, since they don't have the record of my cancellation, it does not matter if I returned the equipment. She then hung up on me. I was surprised to be treated so bad. I now learned hanging up the phone is regular happened at Comcast customer service billing department.
Hi MKhuynh1, by chance do you have a receipt from when the DVR and modem were returned?