I have a huge Calphalon One chef skillet that I have had for about 3 years. I use it all the time and am really careful with it (hand wash only, etc.). I just realized that my non sticlk coating is starting to wear away. What on earch is going on? HOw could this happen? This was a $200 (on sale!) skillet so I am really disappointed. Does calphalon have a warranty (of course I threw out my purchase info)?