So today I noticed there is a small crack at the back of my iPhone 5. It's pretty subtle, but now that I've seen it, it's hard to unsee. It happened between the camera lens and the rim. You can feel it's a crack and not a scratch. Note that I never dropped the phone or anything similar to that (there are no signs of any kind of impact in the area either). I would show you some photos, but unfortunately there's no cam available. What can I do about it? What are my chances in an Apple store?