Cell C
Still taking money off my account!!!

I cancelled my contract with cell c as my 3G internet stick wasnt working. I paid the outstanding amount to cell c and faxed the proof of payment through to the accounts department. I then called the accounts department and they said they recieved the proof of payment and the account would be closed! They are still debiting the monthly instalment of my account! I want my money credited and for this to be finally cancelled!!!