White iPhone 5 sides turning yellow

Just got my iPhone 5 from my plan network yesterday, and I opted for the color white since I've heard the black one is prone to more visible scratches.

After getting the 5, I immediately bought a silicon case for it, so I haven't really had the time to actually "look" at it…

But this evening when I took the phone out of the case to do my OCD check up and clean up, I find the sides of the iPhone are turning into this hideous yellow color and I tried wiping it off, it wouldn't come off. Also the aluminum sides are starting to peel off, revealing a lighter silverish yellow color.

And the worst part is, I can't swap it with another iPhone, since what I get on the first day of plan, I will be sticking with it till the contract's over. It's really bugging me

Added (1). P.S. I live in a little city in the Philippines, so NO, we don't have an Apple Store here, so that's out of the question.

There's rust. Go to an Apple Store. You need it checked and maybe replaced.

Maybe its because of the heat in your hand although it would be red not yellow