@ziby
Try logging into mymobile.o2.co.uk if you can then uninstall the app and the reinstall
If nor then it could be that you are been migrated to the new billing platform, and as a quick search on this community, would have shown a lot of people have the same issues, but seem to fixed after 24/48hrs
- Xperia 1V - o2 and Spusu
- Pixel 8 Pro - o2 and Vodafone UK
