on 30-10-2014 14:04
Sorry, I wasn't to know you had ported from EE.
If the sim swap has started, which it sounds like it has, you just need to put your O2 sim in the phone (assuming phone is unlocked) and keep on rebooting it until you get a signal - It can take up to 24 hours to work fully.
Or even earlier if the OP is lucky @MI5 ...(I always check for my own benefit...and knowledge..)
on 30-10-2014 14:05
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
on 30-10-2014 14:10
Porting the other way from O2 to EE literally took minutes and was done 2 hours before the time given by EE.