Being charged for ADSL that is not installed in my home

I have inquired for ADSL to be installed in my home 4 months ago and they came back to say I need to pay R700, which I did pay and have been waiting since for installation. But the worst part about this situation is Telkom has listed me in the Credit bureau as I have not paid them for the past four months. I am not utilizing the service yet my name is and credit record is been destroyed. I have been calling with no assistance.