Worst Service I have ever received

I took out a Smart broadband wireless contract with Telkom Mobile. Open taking this router home i noticed that the 3G coverage on the telkom website was incorrect and I didn't have any coverage for this product to work. I Called the customer care line a number of time to ask Telkom to come out and investigate with No Joy. The calls i logged got canceled a number of times without s single call from Telkom. I have had an extremely rude agent hang up on me aswell. I finally had enough of trying with Telkom and requested a cancellation which was sent through on the 10th of March. I have followed up with countless emails and calls and each time I get a promise that a Manager will call me back to resolve but till this day I have not heard a single thing from Telkom. I called the call center today and was told that they have a back log in cancellations. Now should i have to carry the cost of this back log because telkom have terrible coverage and even worse customer care?? If Telkom Mobile read this i request a call from a senior manager to resolve this and refund the amount i have paid because of your backlog.