A few options:
Customer relations:
Virgin Atlantic - Customer Relations
PO Box 747
Dunstable
LU6 9AH
UK
or email
[email protected].
Also, you could comment on the VS Facebook Page and Greg will usually provide his personal email address which I know he does forward on.
TBH, the customer relations route is probably the best as you do get a response to say it's been passed on.
Luke