Cannot get cancellation since end Jan fianlised

It has been almost 5months now trying to cancel my internet services on my line by Telkom, I have moved over to another company. I have sent emails' faxes exc. A lady called on the 12May and apologized for the delay from 021 number and said my bill will be rectified from Feb and all will be cancelled as from backdated to 28Jan. She said she will send sms with ref no