Cancellation ignored

Cancelled contract 18 Dec 2015, still active and when I phoned to ask why my account is not cancelled they said it is still in the queue for processing. I was under the impression that I only need to give one month notice to cancel a contract and not that you need to wait until one day they decide to activate the cancellation; in the mean time Telkom deduct the monthly fee from my bank account and pocket my money<br>