Credits don't usually show until your bill is generated but you can check by following the guide here
https://community.o2.co.uk/t5/How-to-Guides/How-do-I-know-my-Community-reward-has-been-applied/ba-p/...If nothing is showing, you'll have to chase it up with customer services.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)