To view (listen to) on an iPhone, follow these steps. Blocked callers’ voicemails are not deleted; they are saved in a hidden folder.
If you have scrolled to the bottom and do not see the folder, consider the following: how to view blocked voicemails on iphone
If you realize you blocked someone by mistake while checking their voicemail, you can unblock them directly through your phone settings: Blocked Phone Number Voicemails - Apple Support Community To view (listen to) on an iPhone, follow these steps