i Phone 3G - keypad locked on me. Bell sign appears in screen - help?

[nickylad]

I have just had a new i phone 3G for two days and it has just locked up on me. I can turn the phone on but when it asks me for the passcode it will not accept the code. It receives in coming calls but no other function works. A bell sign appears in the centre of the screen. Is there anything I can do to restore the phone ??? Help please