Defective Disk

Greetings, I have an issue with my disc not reading, after getting this game I noticed that the disc is "discolored" or part of the underside of the disc has a sorta camo effect going on with the color tone of the disc. (this is not to be confused with the written part of the disc)

So this worked for several weeks without issue, but since the last update to xbox 360 the disc seems to no longer read properly or fails to read during optimizing HD content. (something I did not have to do previous to this update)

I would like a new disc if this is possible or digital copy, I can ship this to your company so that this can be examined to validate my claim. Returning this to the store is not an option as they will not take an opened game. I have looked to the help guides and tried all other possible solutions but have yet to find one that works. Thank you.