Still being billed for a cancelled contract

I took out a data contract with Telkom for 24 months. In September 2015 I went in store to the Table View Bayside branch to cancel the contract, I have them a month notice and the contract was supposed to have been cancelled in November which is when the 24 month period was now over. However the contract was never cancelled and they have been deducting money from my account each month of different values as payment for this cancelled contract. I then went back to the store to see what was going on, they advised me that the cancellation had been logged on the system but was not put through. (February 2016) They then referred me to customer care which I am now dealing with being shoved from pillar to post with no real answers and being told my account cancellation only went through in February after the second time of me going in store to follow up on what Telkom should be doing. I have done my part as a client to ensure I cancelled and gave the correct notice and paid all my bills on time for the last 24 month. All I am asking is for the money to be paid back to me that was deducted after the account was cancelled. This is fair I believe.