POOR QUALITY LE CREUSET PRODUCT

I HAVE 24CM NON SCISK PAN FOR ABOUT 5 YEARS. COST ABOUT R 2600. RECENTLY WE HAVE PROBLEMS WITH CLEANING THIS PAN AS DEPOSITS ARE JUST STICKING TO THE SURFACE. WENT TO LE CREUSET SHOP AND WAS TOLD THERE IS LIFE TIME GUARANTEE ON EVERY PRODUCT. HOWEVER THEY CAN'T RESPECT MY COMPLAINT AS I WAS FRYING STEAK AND SCREMMBLED EGGS ON IT. I DO THIS SAME WITH OTHER CHEAPER PANS AND ALL IS FINE. SO WHAT IS ALLOWED TO DO IN THIS PAN. BOILING WATER? NEVER WILL USE THIS SO EXPENSIVE AND POOR QUALITY PRODUCT.