Hi ​@Twixxy99 

Sorry to hear that iMessage is not working they why you want. Can you try the below please.

I would kindly ask that you check the following for me:
 
Please go into the phone settings so that you can change your number. Then go to "Phone", then "My Number". Please enter the correct number and use "+44" in place of the first "0" of your number.
 
Now go to settings again and then "Messages". Make sure that the iMessages is turned on. Then go to "Send and Receive Number", and check if the correct number is selected.

-Michael

Thank you but I’ve tried that and still won’t work 

Hi ​@Twixxy99 Can you please try the following as well.

1. Go to Settings > Apps > Messages and turn off iMessage. 
2. Go to Settings > Apps > FaceTime and turn off FaceTime. 
3. Restart your iPhone. 
4. Turn iMessage and FaceTime back on.

~Marquerita

Hi, I’ve done all of that as followed the info on id page , iMessage will not turn on , FaceTime has but still cannot be used .