Lots of complaints about the app
Can you use https://accounts.o2.co.uk/signin?
If so delete the App, reboot the phone and reinstall
Otherwise
You will need to contact O2.
Message them on Social Media. Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG)
Or phone them on 202 or 0344 809 0202 (contract)
This is not O2 and we are all customers here similar to yourself and cannot answer account type queries.
