on 21-09-2012 19:31
Have you transferred your number to a nano sim? Maybe it hasn't been fully provisioned yet.
Try rebooting the phone.
If that isn't yor problem check for any issues in your area.
on 21-09-2012 19:43
on 21-09-2012 19:50
After 2 hours, my mico sim was de-activated but I still couldn't use nano sim having waited a further 2 hours. I decided to turn my iPhone 5 off and then on again - and it started working!
Give it a try...
on 21-09-2012 19:54