Wireless provider? Are you unable to send, receive, or both? Is iMessage working w/ other iDevices?
I have the same problem. I bought iPhone 5, factory Unlocked in USA 2 weeks ago. Got the new nano-SIM card from Airtel, India.
After activation, everything works fine except that i cannot receive SMS from anyone (though i can send SMSs without trouble).
Will appreciate anyone helping me?
thanks,
Priyank