you would need to call Virgin customer services on 789 and ask them to reset your voicemail.
Once they have done this you can run through the setup procedure explained in this link:How do I set up voicemail
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.
Welcome to the community. Thanks for taking the time to post.
I see AlexKid has provided you with a great answer here. I'm just stopping by to see how got off with this. Have you had this reset now?
Let me know if there's anything else I can help with.