Samsung SGH-U600 "curv mark instructions" Questions

My Blackberry is hanging on the Memory cleaning application. The front screen shows only the ''Timer''. When the phone is reset and the sim card removed the phone keeps going back to the same screen. ...

...I have had my phone for 3 weeks and yesterday the screen only showed about 1/3 lit up with a curve across it and the rest black. I took it to the dealer and they say it is cracked and I need