Cannot cancel a line....even with notice...

I have been trying to cancel my line as I am moving and when I phoned after a month to get confirmation that it has been done, I was told that it wasn't. I tried to be put through to the department only to be told that there is NO WAY I CAN SORT THIS OUT and that they can escalate it if I would like. Then they hung up on me. I called back. They hung up again. I have just tried again and got disconnected again. I cannot believe that this process is so bad. Telkom are very quick and efficient when it comes to selling products but disconnecting and cancelling they are pathetic.