You're not supposed to use metal scrapers, it removes the teflon. George Forman grills come with those funny plastic spatulas that you are meant to use for cleaning, if you return it they will probably tell you the warranty is void due to negligent use (its worth a try though).
That having been said, just wash off the teflon chips, it will still work, it will just have lost some of its 'non-stick properties, so you will need to use oil/butter/margerine to prevent sticking. (I know this because my husband tried to scrape our sandwitch maker with a knife and the same thing happened, but it still works fine).
