have you tried manually searching for a network?
Before you left for your holiday did you check that your mobile account was set for roaming?
you can do this now by logging into your account and click on the "Plan and device" tab.
Go to "Manage my services" - "Roaming" needs to be ON & "International call barring" needs to be OFF
Allow time for your account to update then reboot your phone by turning it off & on again.
If you still need help, you may be able to use the web chat option to speak to an advisor starting from here: Help and Support - Contact Us > Mobile > Mobile not working > Chat online.
The advisors are often busy though so you may not get connected straight away.
Otherwise, if you can borrow a phone to call Virgin Mobile their UK support line number is: +447953 967 967
Have a great holiday
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.