To stop voicemail use the web account or ring 789
to turn off voicemail yourself. Log into your Virgin Mobile account
Click on the "Plan and device" tab then go to "Manage my services".
Here you will see "Voicemail". To turn it off move the "switch" (click the other side of the rectangle box).
Allow time for your account to update then reboot your phone.
Or as J0hn said, you can call customer services on 789 and they will deactivate it for you.
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.