Original set? Still under warranty?
No fear. I faced this problem before.
Just send to the nearest nokia care center. Make sure they got spare part.
Will take only less than 2 hours to fix it. 

u r lucky enough.lucky u r ORI set.if u r AP set..haha.

when exactly does this screen problem occur? mine i faced b4 when i try to change theme or wallpaper, but the cause was due to a corrupted theme file in my memory card, so you might want to check that out first before sending.