Iphone 4s Screen Permenently Smudged

My IPhone 4s screen has smudge marks all over it that wont come off. I tried using a microfiber cloth to wipe off the smudges and it seems to just get worse. I used a little bit of water on the cloth to clean it and that didn't help either. I tried using a soft paper towel and my shirt still the smudges seem to get worse. I then tried using a cloth used to clean a computer monitor with just a little bit of Isopropyl Alcohol and Water (the cloth was mostly dry just a little damp) and that didn't work either. For the past few weeks the screen feels like it has eraser shavings on it and I always have to wipe it off. I'm wondering if this is a sign the film over the screen was deteriorating. Has this happened to anyone and if so, how did you fix it? Please help.