Can't log on to my o2 app

[Amber1820]

I am unable to log on to my o2 app 

[jonsie]

O2 have totally messed up a change to a new billing system which is effecting thousands of customers.

You'll need a new email address that's not been used on O2 before. O2 for some reason have used redundant legacy o2.co.uk emails on some accounts

This is a customer to customer community, not O2, so we cannot access your account, sorry.

You need to contact O2.

Try online https://mymobile.o2.co.uk/
Or you can try messaging them on social media although it's not an instant response
Use the links immediately below 

Guide: How to find help & contact O2