Underbody Shield problems of the 2005 Toyota Matrix

I was driving and discovered the a/c in my brand new 2005 Toyota (still under warranty) Matrix was blowing warm air instead of cold. I took it to a Toyota dealership. After looking over the vehicle, the dealership gave me a diagnosis and repair price. The dealership diagnosis was "a rock had bounced up into the engine and penetrated the condenser" dealership informed my part and labor wasn't covered by my warranty. I pointed out it was a design flaw because no protection (I. E. Shield) to the a/c condenser. File complaint with Toyota of torrance CA and given a case number. Dealership continues to say warranty doesn't cover the repairs. I pointed out the lack of protection and design flaw.