Direct TV Stealing off Debit card Internet

We canceled our services with Direct Tv due to the bill was never the same. We were with them for over 20years. We happend to want to upgrade our receiver a year ago, but never activated it until this past year. They said they put a new 2 year contract on that new receiver, even though it had already been a year that we upgraded.  They told me over the phone, we have to pay for the 2yrs cancelation fee, if we did not they would use my card on file. I just received the bill  about a week ago, and they have already took the funds off my debit card today, drained the balance in my account over 500.00 was stolen. They did not have authorizaton to do this. Watch out for this company, everyone.