Try this, It works on the other devices that have VVM, Not sure if it will work on the Blackberrys though.
Tap the voicemail app, Menu, Compose, Record(Just a few seconds), Send to firstname.lastname@example.org.... that is v v m, Once you send it give it like 2 mins and if you have any messages in the mail box they will all come through.
It's a known issue on the blackberrys that come with VVM as a feature, that they do not have a compose option in the VVM application. This was and is part of the problem that Sprint is working on resolving in an upcoming MR for the bb Style and bb Curve 9330. In the meantime, a toggling or refreshing of the VVM feature thru the billing system, (tech support can do this) can restore functionality of VVM and has been working for most. What's not working are customers receiving multiple notifications for the same message or receiving an sms from 9016 FOR a VVM message.