My iPhone 5 sounds like the battery is loose?

I have a iPhone 5 that I bought from someone, it was new in the box. I just now noticed when I move it around and shake it, there's a noise that moves around. I'm guessing it is the battery loose. I checked the IMEI of the iPhone, and it says it still has a 1 year warranty lasting till October 1, 2013. Since I'm not the original buyer of the phone, can I still bring it to an Apple store and exchange it for a new one?

Because I've read the warranty stays with the phone, not the owners, if that's correct.

And if they do replace it for me, will they give me a new iPhone 5 in same color? Or a used one?

Added (1). So should I just bring it to an Apple Store? I called an Apple representative, and he said that it's normal and it's just the camera focus or something…

But I'm afraid that might not be the case…

IPhone 4 or 4S versus LG Cosmos 2, money wise?

So I really want an iPhone. Desperately. But my parents are big on cost. I was having trouble researching the cost difference, monthly. Right now, with the Verizon LG Cosmos 2, I have 500 text messages per month and we have like 550 shared minutes or something like that as a family. I would like to compare that to the unlimited data and text for a Verizon iPhone 4 or 4S, so I can help pay. Can someone help me find this information Please?

How to fix iPhone 4S Wi-Fi problem? - 1

My Wi-Fi stopped working on all my devices at first, but soon started to work on all the rest except my iPhone. It's not a Wi-Fi problem obviously now, so how can I fix it on my iPhone?

Do luxury name brands make iPhone cases?

I always see Louis Vuitton, Burberry, Chanel, etc.cases but when I looked at those stores I didn't see cases. So are the cases I'm seeing real or fake. And if they're real where can I buy them?