I've never heard that theory about not installing an air conditioning unit around a kennel, I wonder if that's a big fat lie. I think I would be tempted to get one of the window type units, if it was just in a garage; they are much cheaper to replace. I'm not sure which company you were dealing with; I think one of the hardest things about living in AZ in finding a reputable company for anything. Please report it to everyone you can, I would start with the AZ board of contractors,
Arizona Registrar of Contractors, it's also a good place to check when you hire a contractor, you can see if a company has any outstanding complaints. Once you complain about them they will be much more likely to resolve the problem. I'm so sorry you are having this problem. Air conditioning in AZ is not a luxury, it's a necessity, and it can mean the difference between life and death.