Continually breaks down

Microwave was purchased for new construction in July 2010 but was not used until Nov. 1, 2010. It has had TWO repair calls replacing the magnatron, the capacitor and the diode. It has stopped working for the third time now and the warranty expired 2 months ago (using the July date). I would consider this item to be a LEMON and should be replaced by Whirlpool. They refuse to exchange it and suggested that I find another repairman and not use the one sent by the company where purchased.
I WOULD TELL ANYONE NOT TO BUY ANY WHIRLPOOL PRODUCTS. THEY DO NO STAND BEHIND THEIR PRODUCTS.