rebate dispute

We ordered and self installed at&t high speed internet in March of 2007. We kept the service for 60 days, then cancelled because the service wasn't any faster than our dial up. When we signed up, we were told that we would be eligible for a $50 rebate if we kept our service for at least 60 days. We sent in all of the needed forms in June of 2007. When we did not hear anything from them, we called at the beginning of August to find out why. We were told that the claim was denied, they did not know why, but they would resubmit the claim and we were to call back in 2 weeks. When we called back on August 27th, we were told that there was a problem with an insufficient bill. We told them that we had the service 60 days as per their guidelines and the bill was always paid in full and on time. They said to call back in two weeks. We called back on Sept 14th and were told that we were told the wrong thing originally. They don't resubmit rebate requests there and we should call back in two weeks. We asked to speak to a supervisor. We were told that none were available. We called back on September 24th and were told that a supervisor would call us within 48 hours. When none called, we called back on September 26th. Again we were told that a supervisor was not present and they would get back with us in 48 hours. We still have not heard back from anyone at AT&T. Each time we have called, we have had to wait anywhere from 8 to 10 minutes.