Trouble changing my primary number

[MarkMead]

When I joined Smarty I ported my number from my previous network. Everything worked fine. However, the phone number shown in my Phone settings (IPhone SE) is the  original number the Smarty SIM card arrived with, and not the new number I have ported. I have tried to change this manually to my correct number, but it just won't change (more precisely will not save the change). Any suggestions of what I need to do? Thanks

[MSF]

@MarkMead  A quick search on this would show that it is frequently asked.

A network reset in the phone settings should sort it if the port process has gone correctly.