So. just set it up as a new iPhone and you should be fine!! No joke before I restored from the back up everything worked.
Tried that as well.
Here is a list of everything (that I can remember) that I've done:
- Putting phone into airplane mode, then enabling Wi-Fi
- Changing DNS of Wi-Fi connection to something like 8.8.8.8. etc
- Logging out of my Apple ID
- Making sure my mobile number is correct for my Apple ID
- Making sure my payment information is up to date on Apple ID
- Changing my mobile number in Phone > My Number and then changing it back
- Turning iMessage/FaceTime on and off, rebooting phone (multiple times)
- Changing Date & Time to "set automatically"
- Reset Network Settings
- Reset all settings
- Erase all content / settings from phone and starting over
- Creating myself as a contact and adding my Apple ID email address & telephone number
- Restoring phone to multiple iOS versions
- Setting up phone as new on multiple iOS versions
Literally nothing I can do will activate iMessage again. And Apple has no idea how to fix it. :\