Landline Cancellation - Impossible?

2017/12/03 - Telkom Land-line & ADSL written cancellation sent on the Telkom Contract_Service_Cancellation form to ********** Autoresponder acknowledgement received - case ********** 15 2017/12/13 - Email from ********** acknowledging cancellation. Indicated that they could not get hold of me (mobile number was completed on the cancellation form and included in the signature of the email. I notified them that they should not attempt to contact me on the landline to be cancelled, as the premises has already been vacated. After several phone calls to 10210 and emailing ********** I have had many promises that the line will be cancelled and I will be refunded from Dec 2017. Still receiving the monthly Invoices - Debit Order is still going off my bank account every month?