Air Conditioner problems of the 2002 Chrysler Pt Cruiser

I kept smelling this stench odor in my car, it appeared to be coming from the air conditioner. I though maybe either a cat or baby squirral got up in the engine & died. Could not find anything, so we took it to the dealer, since we could only smell it when we turned on the fan. The dealer in tampa knew right away what the problem was, said mold was growing in the air vents, and flushed a chemical in there to kill the mold. That only temporarily solved the problem, so I took it to a different dealer, closer to my home. Told them to fix the problem, not just mask it with chemicals. They claimed the car was coming from something other than the air conditioner & air vents, and refused to fix it. I called the Chrysler ho, and they sided with the dealership.