Telkom Mobile Account Cancellation

For 3 months now I have been trying to get a Telkom Mobile account cancelled. I went into a Telkom branch and they gave me a cancellation form which I filled in and emailed as instructed on the 28th December. The line should have been cancelled by the end of Jan. I even switched off the router then and have not used any of the data. Since then I have re-emailed the cancellation form to at least 2 people at customer service who have said that they will immediately give it to a supervisor to cancel but this has still not happened - almost 2 months later. This is pathetic service and you are now trying to debit my account for almost R4000 when this should have been cancelled. This is extremely frustrating and I have no idea what to do as no one at the call centre has a clue or any authority to do anything. Will never have any further dealings with Telkom.