I called GMC to have them fix an issue with my AC unit. Someone was able to come out that same day. He arrived on time, and even gave a warning call to say he was on his way. After he left the AC was working until the night when we began having issues again. I called back and the receptionist was very helpful. The tech was very apologetic and sorry that he had forgotten to check a component that he should have. He came back and resolved the issue free of charge. It all worked out in the end.