Can I Return My Scratched Phone ?

Last week I bought a new Nokia C3. Its working brilliantly but 5 days later the screen is scratched in many places ... I'm just wondering if I have any chance of changing it for a new phone of the same model in the phone shop ? ... bearing in mind that i DEFINITELY did NOT drop it and its only a few days old ? today i put it down on a marble floor face down while i was cleaning , but i cant see how that could scratch it in THREE places? and i really did place it on the floor very gently ... what i really want to know is am i eligible for a new phone ? Id really appreciate answers especially from a phone specialist ,Thanks :)