Billing and Accounting

I've had an I have had an ongoing issue regarding billing for 3 years. I have tried to contact regional managers and they literally tell their employees to tell me he cannot help me. I was told by the tech who installed my service that there was a big promotion going on and when I checked my billing which was automatically withdrawn from my account months later I discovered that I was being charged for services I did not ask for. I have discussed this and detail two dozen times with customer service and they do not help me even though they told me that they will nothing has changed. I need some help with the situation because no it is showing up on my credit and I'm trying to purchase a home. Please help me asap!