American Airlines has the worst customer service.

Im about to compose a full blown complaint but just to blurt a brief summary. I recently purchased a trip to Brazil via the AA website, and one leg they allocated via a different airline. On the return I missed the flight, well when I called AA they said there was nothing they could do. The ticket was via a differnt airline and refused to help me get credit or rebook the flight. They wouldnt even help with the leg of the return that has AA as the carrier. AA rep said it was because I didnt use the third party leg yet. So basically to use an analogy, If I rent a car from HERTZ and there is a problem would they send me to the automotive dealer for repair instead of replacing the car they rented me??? WTF!