Hi ​@Xsimoss 

Have you received a ‘Welcome’ email or SMS from iD Mobile to confirm your switchover?
To confirm your PAC code has been received by iD Mobile and your number is being ported over, you should receive a text message from iD Mobile confirming the transfer. This text will typically arrive within one to two working days of providing the PAC code to your new provider, especially if submitted before 5:30 PM on a weekday. You can also check if the port is complete by inserting your new SIM card into your phone and seeing if it connects to the iD network and receives calls or texts. 
https://www.idmobile.co.uk/already-switched

The provisional iD number tends to be retained by the phone when the iD SIM is inserted too early, but this should sort it. Its a fairly common issue:
https://community.idmobile.co.uk/switching%2Dto%2Did%2Dpac%2Dstac%2D132/why%2Ddoes%2Dthe%2Dwrong%2Dnumber%2Dshow%2Dwhen%2Di%2Dmake%2Dcalls%2Dor%2Dtexts%2D32301?tid=32301&fid=132

If you need any further assistance then contact the Live Chat:-
https://www.idmobile.co.uk/help-and-support
Type ‘talk to a person’ in the dialogue box to connect with an adviser (rather than going round in circles with the chatbot). Make sure you have time to connect as it may take a while for the chat to start and to get replies as the advisers usually handle a few conversations at a time.

Also, the simplest option is usually the one that works…. so have you tried turning your phone off and then on again?

I hope this helps x