Telkom Mobile no help when you need to cancel!!!

I took out a contract with Telkom Mobile for data services at my home office I was told there was good reception in my area when I setup the router I had such bad signal that the signal kept dropping and I could not even download emails never mind go onto the internet to make a payment in the bank. I went back to the branch in Ballito and asked for the services to be cancelled as there was no reception. This has been an ongoing process now since last year September and to date I am still waiting for them to cancel the contract due to non service and keep getting billed every month. Have phoned the call centre 4 x alone in the past 2 weeks and still waiting for the cancellation dept to contact me, you can't phone them directly which is very inconvenient. Client Services keep assuring me they have passed on messages this is not acceptable.