Having spent 30 minutes on this on Friday and over 45 minutes on it today, the only way to resolve this issue seems to be to post here and hope for someone from Virgin to reply in a PM.
Previous posts will suggest that we have set a PIN in the past however it is clear from the posts that all of us have no recollection of having done so. Various pages on the Virgin website (including the members area) suggest solutions such as phone numbers that can help but these numbers either do not work or do not lead anywhere.
Therefore save yourself time and effort and post on here and hope for a reply.
Thanks for popping back with the update Justin, glad it was sorted in the end. I appreciate it's more difficult than usual to speak with the mobile teams at the moment and we're not getting to posts as quickly as we'd like here either, but if you do require any further assistance in future please get back in touch.