Messed Up Xbox 360 Game or Disk???? HELPPP?

I just rented M Effect for the xbox 360. I think the disk has a problem cuz a few time while playin i get the message sayin " disk unreadable". My 360 also make weird scratchy noises while im playin m effect and m effect only. (no i am NOT switching the 360 up or side ways). I think its maybe cuz there is the sticker for Hollywood video on top of the disk. Anyways i finally got to a certain level and it brought up the "disk unreadable" mssg again. every time i start up my 360, the game it runs allright until i load the file for that certain level im on. i works for a couple seconds then the "disk unreadable" mssg comes up. the disk is a little scratched up but i dont know if the problem is with the disk or the game. What do i so to fix it?