Stop closing my cases without resolution

I have now sat on the phone for over 3 hours in order to resolve an issue that was created purely by Telkom. After reaching the end of my contract period for a mobile data product, I requested that this service be cancelled,as I had recently taken an LTE contract. I was notified of the 21 day cancellation period, and was happy with this. 2 months later, I was billed for both services.<br> <br> After contacting Telkom call center, I was informed that the service was not cancelled, as my request was moved to the retention department! This is theft. I cancelled the service, and was notified of such. If Telkom wishes to retail customers, they need to do it within the 21 days. I cannot be forced to pay for an internal business decision. <br> <br> I have created 3 cases, each time being told this is a back office function and that my case will be escalated. Each time my case is closed without any feedback. Furthermore, my most recent debit order still suggests that there are errors on your side.<br> <br> I am beginning to lose my patience with your service, and will be cancelling my existing LTE service if no resolution is found.