I have previously posted about problems with my AC - both at "home central" and at a vacation home. Both related to problems either missed or not properly repaired that eventually required my own investigation and solutions. One company sent out a total of 5 technicians over a period of a few weeks without satisfactory results and another company's tech missed a big safety issue. The lack of integrity and concern prompted me to write complaint letters to both companies. After they received my letters, both companies called me to personally discuss the issues - both calls were civil and constructive. One company dropped all its charges and credited me a charge I'd previously paid (total of $300 +) and the other company sent me a partial refund. Both seemed genuinely concerned and admitted to the problems. My suggestion is to send a personal complaint letter when it is warranted - it may save you some dough that would otherwise be wasted on poor service. Any reputable AC firm will be appreciative to know of your concerns and problems with their service.