After researching online, I could not find a solution to the problem addressed by this topic. So I called Sprint and a wonderful Rep had an email telling her how to fix it.
This is what we did:
1. Menu - Settings - System Updates - Update profile.
2. Reboot the phone.
3. Locate and launch the Voicemail app.
4. Menu - Compose
5. In the To field type
activate@vvm.sprint.com
6. Touch the red Record button - wait a couple seconds and click the Record button again.
7. Click the Send button.
Wait a couple of minutes at most and all of your voicemails will be rerouted and show up in the Visual Voice Mail app window.