Moved abroad and lost my O2 SIM. Overdue bill cannot pay.

[H2O_LDN]

I've been involuntarily ported over from Virgin to O2 and now have moved abroad. My Virgin phone bill used to get taken out of my Virgin direct debit. Now I am apparently with O2 and have received an email about an overdue payment. I cannot log into "My O2" as (1) I am overseas and (2) I have actually lost my SIM card. How can I pay for "My O2" account? It is weird as it seems, whilst I am receiving the bills via my email, when I log in to O2 with that email, it states that there are no products available. Any help would be greatly appreciated.

[MI5]

@H2O_LDN 

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

You can get in touch with Payment Management team on +44 800 902 0217 who’ll find a solution that’s right for you.
Payment Management opening hours:
Monday to Friday – 8am to 8pm
Saturday – 8am to 6pm
Sunday – 9am to 6pm

You can use Skype to call for free Guide: A Guide to Skype 

Also needs reporting as lost to O2 Guide: Lost or Stolen O2 Device? - How to Report it