Obviously there is something going on with the way you handle your phone, and its very possible that is it something on your hands causing this to happen. secondly you should buy a case, even the new apple cases are pretty damn close to naked but will protect the bezel and back of the phone from whatever is causing this to happen. if your leather case starts falling apart from your "oils", you should go see professor x you may be the next member of the x men with supernatural corrosive hand oils.