Hi,
Whats happened to your iPhone to stop it powering up ?
Try holding the top power button and home button together until the apple logo appears and then let go. It should re boot.
Or hook up to itunes and perform a DFU procedure.
http://www.iclarified.com/entry/?enid=1034
The other answer is put your sim in another phone such as a friends or families to divert calls.
If the alternative phone takes another sized sim card then sim adapters can be picked up from any o2 shop for free.
Or ring o2 CS for assistance.
Numbers are in the 'contact us' tab at the bottom of the forum page.
Divert calls help link : http://service.o2.co.uk/IQ/srvs/cgi-bin/webcgi.exe?New,KB=Companion,question=ref(user):str(Mobile),C...
