I recently purchased an unlocked nokia 6650 cell phone from e bay
when I put my sim card in dialed my # it went straight to my voice mail. When I tried to dial out it has an "emergency use only" mess on the display
I had the same issue with a used phone. An easy fix is to remove and reinstall the Sim card, at which point a message box will appear that asks if you want to stay offline. Choose "no", and you can now make calls to anyone.