I am having a similar problem -- I know how to access the Message Centre setting but it won't let me .... options of only HELP or EXIT.
The phone (a Nokia N73) was given to me by a Network 3 user. She had it unblocked so I could use it on my O2 network but, despite calls to both networks I cannot change the number.
Can anyone please tell me what I can do? Take it to a high street person who will remove all the software so I can start from scratch??
Any suggestions would be more than welcome!
Thanks!