Telkom does not honor the Cancellation request

I cancelled my Telkom but they keep on deducting the monthly fee - i don't know what to do anymore. I have gone in to Telkom offices on numerous occasions, but it seems like i am wasting my time. I have proof of the cancellation as well as that i returned the device, the "Consumer Contract and Services Cancellation Request" was signed by myself and by the Telkom office on 17 October 2019. can anyone help me with this? I need my money to be refunded to me and the deductions to stop immediately.