Cancellation of account and still being billed

I called Telkom call centre to find out if I could move my line to my new home. The call centre agent instead tried to sell me several packages. When I refused, he told me I can't move my line and that I had to cancel it and put the phone down on me. I then called back several times and was told that I needed to send a form to the cancellation and mailbox with all my documentation. I did so on the 2nd of August as I was moving at the end of the month. My line has still not been cancelled and I have been charged every month with interest! It's also affecting my credit status. I have called telkom over 55 times. I have emailed, I have tried to contact them on social media. I even logged a Dispute twice. I was promised that it would be escalated. I even got an agent to move my existing line (I was told that I **** to by the previous agent and that my line can be moved). And yet NOTHING has been done! What a joke!

No one can help and there is no way to get in touch with this mysterious cancellations department!