Cancelled contract is not cancelled

Dear Sir / Madam<br> <br> In November I cancelled my 10Gb per month data contract, giving one month's notice for mid December when the 2 years would expire by visiting Hatfield Telkom mobile centre. In mid December visited them after my account was debited in December, they assured that it was finished and would be the last payment. Since then I have paid in January and February. Can this matter be urgently looked into, and all money after the normal 2 year contract paid back to me.<br> <br> Thank you<br> Grantley Sherwood<br>