Sent to collections and credit dinged

Back in early May of 2014 I had the bright idea to switch my interent and home phone service over to ATT U-verse... and then the nightmare began. Within hours of the service being installed my internet was down. I called customer service and was instructed to reset the modom which I did and with in 10 minutes it was down again. A tech came out the following day and informed me that I should have never been sold the service because I was to far down stream from the signal and that was cause of my problems. I cancelled the service and sent the equipment back and was told my account was clear and free, or so I was told. In early June of 2014 I received my first bill. I called customer service and was told that the Eqipment I returned had not been processed yet but as soon as it was my bill would be taken care of. That never happened. I have been on 6 different calls to date and they are all the same, about 30 minutes long with multiple transfers and at the end I am told every time that the matter has been resolved. To my surprise in December of 2014 I received a bill/notice from a collection agency, I agian called and went through the half hour long circus and once again was told not to worry the matter had been resolved... well not really. I am in the process of refinancing my home and was informed by my lender today that my credit has been dinged due to this never ending matter. I called again today and after 44 minutes and 4 transfers I was told I would be called by a supervisor in 1 to 2 hours to reslove the issue. The call never came. The worst customer service I have ever experienced. I cant wait until my wireless contract is up in August and I can sack the whole program. Where do I go from here?