if you can use another phone you can call the Virgin Team on 0345 6000 789.
Otherwise try web-chat : Help and Support - Contact Us > Mobile > Your Account > Chat online.
The advisors are almost always busy though so it may take a while to get connected.(Use a PC or laptop and keep the page open, just refresh it every few minutes until chat becomes available).
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.