Call *86 on Verizon Wireless or U. S. Cellular. Press and hold 1 if you are on AT&T, T-Mobile, Sprint, Cellular One, or Metro PCS.
If you already hung up, the only way to recover a voicemail is through third-party programs.
Some devices will have Voicemail as its own app. If this is the case, then check your app drawer for Voicemail.
Your device may also list this option as Undelete. [2] X Research source
