After spending numerous hours on the phone with Comcast's Billing and Technical Departments for the same reason (suddenly being charged by their Escalations Department for a modem rental, even though I purchased my own modem and returned theirs over 2.5 years ago), I am no further along. I just filed a complaint with the PA Public Utilities Commission. If they cannot help me, then I'll move up the ladder to the FCC, as this is outright fraud.
I agree with DougWS, as Comcast is just becoming too tiring to deal with...
Hi gmortell, I can assist reviewing this further for you. Please send me a private message with your account information (your name, and phone number).