Charged for a TV Box that I do not have.

Hello - 

I noticed on my bill that I am being charged $14 per month for a TV Box that I do not have. I notified Xfinity and requested that the charge is removed as I have been apparently paying it for many years. So, the charge is now removed but I need to recover the cost of all the previous years $14 per month charges. Can someone advise me?