cancelled contract but still deducting

On the 15th August 2014 I have cancelled my 24 months laptop contract because it reached an end date and I did not want to continue with the contract, I contacted telkom mobile and went to the branch at Century city to stop the monthly fee of R40.To-date the fee has not been stopped as the deduction of R40 is still continuing.<br> I'm requesting a refund from September 2014 till to-date