It's known for some iPhones to have this because the 'glue' apple use to bond the parts of the touch screen together hasn't properly cured yet. If it doesn't disappear after a few days then take it back. Just remember to un-jailbreak it first ...
I donno if it's possible cause I bought my phone from USA but I'm living in turkey right now .Yes there are lots of apple stores but I don't know if they accepts mine (