Debit account after cancelling contract

On 21 November 2015 I went to the MTN store in Northgate to cancel may data contract which had already expired. I had tried to call the numbers provided to cancel the contract before, but got no joy. At the store I stated that I wanted to cancel my contract and provided all information and documentation necessary. I was emailed on the day to say that MTN was cancelling the contract and on 25 November I received another email to state that the contract had been cancelled. However, on 1 December my account was debited with the contract fee. I emailed to resolve this, only to be told to call 808 from an MTN number (I am on Vodacom). When I asked for another number I was told to go to the store because calling would be very expensive.<br> <br> I have already been in store to cancel this contract! I did not think it is necessary to specify that I do not want to pay for a contract that I have cancelled. This is poor service, making it unnecessarily difficult to cancel a contract with MTN.