Hi, I've bought an iphone 4s which was unlocked at the end of its contract. Now it's frozen solid. It won't reboot as per the hard reset by holding down home and power buttons. All I get when I do that a close down and new apple logo followed by the itunes logo. Problem is I cannot open the phone up to connect to itunes. The pass code won't allow me to enter a code. All in all I have no idea what to do. Any thoughts?