Incapable of cancelling a contract

The most unpleasant experience we have had dealing with a service supplier has most definetly been with Telkom Mobile who just cannot seem to cancel a mobile contract we have cancelled in store from 01 November 2015. We have followed up numerous times, weekly, with their call centre to follow up the progress of the cancellation and still nothing has been done. First we had to wait 21 working days. Fine, we did. In the meantime we called in to make sure that is happening. After 21 working days we were charged again for the contract, and after following up again with the call centre, the case was not properly followed through. We have been keeping in touch with call centre and again nobody knows what going on and now we are 21 working days again from 07 December? Why must I wait 21 working days from 07 December if I the customer cancelled 01 November just because of their system? Why must I pay for something I dont want and followed the right process to have cancelled? Why must I struggle to get the contract cancelled and follow up with them like they are babies to make sure it gets done? Should it not be a simple and painless. The truth is, it is the most painful process.