Close but no cigar

Question

when i turn it on w/o the sim card all it says is "insert sim." i keyed in the number you gave me with the sim card in and it popped up "unexpected data." i tried to do the master reset but it asked me for a security code and i had no idea what it was. . .i don't want to get locked out of my sim by trying the wrong code too many times.

any other ideas?

thanks!