Charges for cablebox never received and servi rs that I canceled

I have been being charged for a cablebox I never got. Furthermore, I had initially returned a cablebox to cancel 1 of 3 I did have. This is not the first time this has happened. This also happened for the internet box I returned (the internet was always going down a couple times a monrh which is bad when I work from home). Seems to me the is standard business practice for comcast to fraudulently charge it customers to boost their revenues. It would be onw thing if it happened once, but to happen twice is upsetting and looks to be intentional.