Not paying for a service I'm not receiving

3 years ago I open up an account for a landline to me put in my grandmothers house ,the landline was not put there and Telkom has been billing me ever since to a point where I had to change banks. We NEVER received the service, it has been 3 years, I have contacted telkom on many occasions and cancelled the account multiple times regarding this ,all they did was to hand me over to debt-in. I will not pay for a service that was not provided.