Email addresses not matching for account

I recently got broadband through Virgin media but have had difficulty setting up or linking to a My Virgin Media account. I already have a My O2 account registered with my email address, but I am unable to register for or link a My Virgin Media account to it as it says the email addresses do not match. When using the 'forgot my email address' link for My Virgin Media, the email retrieved for the account shows incorrectly as "[object Object]". This is despite me receiving the account set up emails to my normal email address.

This leaves me unable to access My Virgin Media or manage my account - how can I update this so that I have a working My Virgin Media account? Any attempt to register takes me to the existing O2 account before it fails to link due to the email mismatch.