Not impressed with the service aftermath

I cancelled my line on the 13/06. I called the call center on the 27/06. I was informed that there's nothing outstanding by Andile. No I have a letter of demand to pat R616.74. I sent 3 emails to the following departments: ***, ***, ***, (11/07) *** (16/07) and ***, ***, *** (24/07) and to date no body has called me to resolve this issue. Instead i get a letter of demand regarding an outstanding amt. REALLY, I'm done. You do everything by the book and now you still get taken for a ride.