The problem is that the techs can't go to contractors carring "brand x" and get the parts because of restrictions put on the contractor by the manufacturer. In these cases, once you get "in" with the bad guy, you are pretty much stuck with him.......Orville, in this case. Other manufacturers do not put on such restrictions, allowing "all qualified techs" to make the repairs, therefore, a way out of a bad situation. In case you end up on a "dead end" street with a bad hvac contractor, your only option(s) is to get another qualified tech to work on your equipment and hope that he can find parts somewhere, or "rig" repairs, thus invalidating the warrenties, or sue.
I might add that other brands other than "brand x" are just just as good!!!!!
Sorry to hear that the "bad guys" work your area. They work ours too. There are untold horror stories. Even good references can't keep you out of harms way..........isn't that a crock!