SENT TO COLLECTIONS FOR FAKE DEBT

After terminating my service upon moving into a new house in an area that does not support U-verse, I was charged an early temination fee even though it was voided because of the unavailability in my new area. I started receiving bills of $152.39. I called serveral times and each time the person I spoke to and explained my situation to told me they had fully fixed it and there was a zero balance. They told my I had a balance of $26.09 but because of the stress I had to go through to get this bill fixed, they would waive the $26.09 and the balance would in fact be ZERO. I received calls and letters regularly and was told to disregard them. I called again after being threatened in a letter to be turned over to collections and the woman, who said she was one of the chief customer service reps, was very rude to me and told me "just dont pay it then". I told her I cant just NOT pay something without it being fixed or it will go into collections and mess my credit up (which I am trying to rebuild). She told me that I would need to wait 5+ business days as it takes the system a while to process the final bill which indeed would be ZERO balance. I just received 2 calls from a collection agency who said the bill is from ATT. I am tired of calling and having people lie to me telling me they fixed the bill and then nothing happens. Now collections is calling. I am in collections for a debt that doesnt even exist. This needs to be fixed NOW.