Poor service delivery - Telkom

I have been trying to resolve a query with Telkom for a installation not done in August and still have not received any feedback even after numerously trying to contact them. this was for a adsl connection, and thereafter a mobile contract. I am still being billed for a service which has not been installed and find the service from Telkom absolutely disgraceful to say the least. Something needs to be done to have this kind of service providers held accountable for their poor service.