Sharp Aquous TV - Contrast problem?

My Sharps Aquous TV has a problem with the contrast on it. A year after we bought it, the contrast went to pot. If you raise it's level above 0, you get a strange green 'aura' effect on people's faces, on shadows or anything with a bit of shine. So now we have a very flat picture as we are unable to use the contrast on it. Is there a simple solution to this or an expensive fix for it.