Hi,
I just had the same issue with my new iPhone 4S purchased fromApple in the UK. Ported my old number from02 to Three Mobile, but iTunes and settings -> phone -> My Number stillshow the temp number supplied by 3 Mobile prior to the transfer. Power cycling and re-syncing with iTunes madeno difference.
My old iPhone 3GS (IOS 4.3) and a friends iPhone 4 (IOS 5)still appear to allow this field to be edited, but not on the 4S.
Fixed the issue by doing:
- Switched off Face Time (Setting -> FaceTime-> FaceTime OFF)
- Switched off iMessage(Setting -> Messages->iMessage OFF)
- Switched on iMessage (The phone started “Verifying”the incorrect phone number, failed and set it to the correct ported number (seeSettings -> Messages -> Receive At -> Phone).
- At this point the “My Number” (Settings ->Phone -> My Number) had also updated.
- Switched on Face(Same “Verifying” as with iMessage, but tooktwo attempts).
- Power Cycled the ‘phone and re-synced to updateiTunes (Summary “Phone Number” field).
Hope this helps!