My 02

[Thissystemisold]

Been months and still can't access the app a window always pops up telling me I have 48 hours to wait. My data runs out in less than 3 weeks. I need to access my 02 to track data usage.

[MI5]

@Thissystemisold 

Try online https://mymobile.o2.co.uk/
If using the app, try deleting, rebooting phone and then reinstall the app.
This is a customer to customer community, not O2.
You 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 give them a call on 202 or 0344 809 0202 (contract) 4445 or 0344 8090222 (PAYG)
Unlikely that you'd get help in store, but may be worth a last resort try.

[gmarkj]

Depending on your phone you can also set up a data counter on there to monitor your usage @Thissystemisold