I have 2 copper crispers and directions say safe for use on grill. My tray turned black on the grill. I would appreciate a replacement tray free of charge since I followed the directions provided. Ive tried to get the black off without ruining the special copper coating but the black wont budge. Can you either give me advice on how to safely remove the black that the grill created to reveal the copper finish or replace the tray free of charge? I do use these crispers a fair amount and am very disappointed that the one is ruined. Thank you. I hope you back up your product and make me a happy, satisfied customer.