Login to VM account

I have a VM account which I cannot access. 

I have a O2 account linked to my Googlemail email address. 

When I go to access VM account I get the 'link to your VMO2 account. I go through the process, it sees I have a valid VM account it also quotes my O2 Google mail account and says do I want to link VM account to it. I confirm I do, it asks for full VM email address and sends an email to it to complete linking. But of course I can't access the email via any webmail address as it sends me back to link your accounts. So I'm stuck in a vicious circle.

Any ideas how I resolve this?