You need CS to enable it on your account
to call customer service
Advice from an O2 Guru to get through:
If you call 202 or any of the free numbers in the link.
Guide: Coronavirus Community Help and Support
Use Skype if necessary, when it comes to the reason you are calling stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
Choose the fraud or upgrade option if necessary
8am is the best time to call them
Track usage, upgrade and get support with the My O2 appDownload My O2