I never planned to be (permanently) hitched to Telkom

To be fair, the service was excellent when it was still required. Now I seem to be chained to Telkom. My contract expired in June. I went to a service shop to cancel and was provided a cancellation form to fill in and email. I filled the form and sent it for cancellation by 31 July 2017. To this day my debit order is still going off. I have complained but there is no response.