Inability to cancel month to month contract

I signed on for a month to month sim-only data contract with Telkom at the end of 2016. Telkom informed me that since it is a sim-only, month to month contract I will be able to cancel at anytime. Unfortunately, Telkom network availability in my neighbourhood is quite bad. Due to the poor coverage I was unable to use the service.

I decided to cancel the service and sent in the cancellation form on the 24th of October 2017. The email was not acknowledged by Telkom. I called the call centre. The call-centre advised me to take the form to a walk-in store. The store refused to process the form and refered me back to the call centre. After a few back and forth I obtained a case number. The cancellation department leaves voice messages for me without any information on how I can contact them. The call centre could not give the cancellation department phone detail either.