When you rejoined Virgin with a new account you would have been given a new email address (even if you never used it). You were a new customer and there was was no reason for Virgin to know there was an old account or old email. In fact data protection would prevent them from copying any data from another account.
So your previous email would have become an orphan and eventually expired.
You will have to see if the IT staff can help, but I fear you must be ready for a disappointment.