Can you check and make sure that this isn't just a licence issue ? The keys for performance and the VM option are separate. So it is possible and I have seen it before that perhaps there is an unused key in your Customer Portal that needs to be applied. If this is the case the VM icon on the home screen for these instance will have a padlock icon on them.
If it isn't that simple Then please enter a support case and we will take a look with you. We want to make sure you get this running.
I'll open a ticket.