My iphone 5 has 3 little white dots at the back?

My iphone 5 has 3 white dots at the back of it, and I don't know how they got there! Because i have had a cover on it since day 1, a proper cover! Not a bumper case, it also has some white dots on the top left corner, what i want to know is if its possible to exchange it?

I think they will let you exchange it if you have warranty on it.

Exchange it for what reason?