Sent to you by Chris Hunter via Google Reader:
iOS Advice walks you through the process in the video above, which essentially amounts to following these steps:
- Open the Phone app and tap the Voicemail section.
- Scroll all the way down and tap Deleted Messages (which will only appear if you have any).
- Select any message you want to restore and tap Undelete.
That's it! No more lost voicemails (if you act quickly enough, anyway).