Unauthorized service charges and misleading billing.

To start, my townhome community used to provide bulk service through the HOA using Xfinity. That was canceled due to rising rates and poor service in the community so we voted Xfinity out. Since then I have been billed for a TV service I have not used in years. $10.00 a month for HD TV service that requires a box I returned about 15 years ago. Not only was that charge supposed to be removed but when the bulk service was canceled I was paying for TV service I did not use. My bill reflects that I do not have TV service but somehow pay for it in my internet bill. This was what the rep told me and had an excuse for every billing mistake I pointed out. 

Is this typical Xfinitity business practices? This is probably illegal and there have been many class action lawsuits around similar scenarious in the past few years for "questionable" business practices. Is Xfinity willing to make this right or do I need to engage others and take this to the next level?