Are you currently a VM customer i.e. do you currently pay VM for broadband services?
If you don't currently pay VM for broadband, and this is just a legacy virgin.net email account from the past not linked to a current VM broadband account, then your email account is most likely undergoing a process of being deleted as VM tidy up and remove such accounts.
I can't say I fully understand the various stages of the deletion process and if/when you might be able to get back very brief/temporary access.
Your query would be better of in the 'Email' forum, rather than 'Security matters', where the regular email experts and VM forum team there can advise. Someone might move it over there for you.
(Edit: duplicate multi-post already exists in 'Email' forum)