I see I can get a free upgrade to v6 box. But I have forgotten all my login details as my payments are taken straight from bank so don't get a statement and I don't know my area code for me71un so I can re-registar.
No, they have forgotten their login details and therefore cant logon to see the bill.
OP, do you remember you virgin email address?, if so go to the login screen and click on the "forgotten my password" link to reset it. Once done log in and follow the advise above, view your bills to get you area code.
You may be better of applying for the V6 box by phone in any case, use the "thinking of leaving us" option.