Sorry to hear you are having so many problems with your new unit. Wow hard to believe that the installing contractor is MiA. Is there a governing body that this original contractor falls * if so you should contact them as all responsibility is the original contractor,s. It sounds like you have tried to resolve this by dealing with the home warranty. I would not give up on the home warranty people as it sounds like you have a number of problems with your unit that requires a good tech. Since the techs they sent you were not able to solve the problem you need to keep the pressure on the warranty people to get them to send a good tech.