Number not ‘associated’ with device after porting.

[Kerry911]

I recently switched from O2 to sky mobile. 
I kept my number and it transferred over fine, but ever since my iPhone still shows that my number isn't associated with my device and will 'expire' from my iMessage/facetime and I cannot fix it. 
I've gone into the settings where you can manually change the number but clicking 'save' does nothing. The number doesn't change. 
how can I fix this??

[caesarome · Accepted solution]

Give this a try @Kerry911 :

Go Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings. Then go to Settings - Phone - My Number and change it if it is wrong, then reboot the phone. You will need to set up your Wifi connection again.

[Kerry911]

THANK YOU!!!!

this worked!!