To delete your voicemail:
From your inbox:
- From your inbox, open the conversation thread that contains the voicemail you wish to delete
- Scroll to the voicemail and long click on the message to open a menu above the message
- Tap "Delete"
From the Calls tab:
- Access your Voicemail
- Swipe from right to left on the voice message you want to delete
- Tap "Delete"
That's it!
*Be careful there is no "undo" button and deleted messages are not recoverable.