2005 Other Toyota Models probs with Toyota Matrix

I recently had to have my entire computer replaced (under warranty) and was told I needed a new serpentine belt and spark plugs. I did have my serpentine belt replaced but am waiting a bit longer for spark plugs. Anyway, I recently noticed that my air conditioner wasn't working and took my car back in. Now they say they problem is my "AC Clutch Assembly," and it will cost over $500 to fix! I'm just wondering if my computer problems could have affected my air conditioner in any way or if something could have happened when they changed my serpentine belt. My car was purchased new, and I've only used my AC for two summers! I'm frustrated to say the least!