Dude, you're an idiot. Apple is perfect. There cannot be anything wrong.

Ok, someone had to say it.

In all seriousness, I don't have that issue, so I'd first check with your mobile device group at work, and then if approved take it to your genius bar. I know my company would flip a lid if I swapped out an iPhone at an Apple store. Company policies differ, however.

My 4s seems to have a loose part inside. It feels like something moving when I tap it, but I don't know if it is natural. My 4 doesn't feel like that.