Hi Stackridgeman,
VM should have send a text message to your mobile which says click on Go to activate the box.
It sounds like it may not have been added to your account correctly.
You could try contacting New accounts and Set Up for them to complete the setup and activation, or fix the systems if there's an error.
That would be options 1,1,1 and 4 if dialling 150 from a Virgin landline , or options 1,1,2 and 4 if dialling 0345 4541111 from any other phone.
It usually best to call first thing on a morning, 8am, when lines are least busy.
Dave
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali