Mike, If you are looking to get it completely disabled, unfortunately, this cannot be done at the moment. To disable the service temporarily, please call us or send us an email at [email protected] since there is a verification process involved so we won’t be able to resolve it here.
With Visual Voicemail on iOS 9 you can listen to a Voicemail easily and you can also save or send a message on to someone else through iMessage or email.

At this point, we can’t be exactly sure why your iPhone won’t play voicemails. The voicemail you play in the Phone app on your iPhone is called Visual Voicemail, which downloads your voicemails from your carrier in the form of little audio files, similar to the music files you listen to inside the Music app.
Follow the instructions and press that number. You will be asked to delete your current Voicemail greeting. Click on the ‘Yes’ button that appears on the screen if you want to remove that. You can save your new recorded Voicemail greeting or can use the default recorded option. From the home screen, select the Phone app. Note: Alternately, you can set up voicemail by selecting the Phone app then selecting and holding the 1 key. Select Keypad, then select the Visual Voicemail icon. Select Start. Select Ok. From any Home screen, tap the Menu key. Tap Settings. Tap Call settings. Tap Voicemail. Tap Voicemail again. View the voicemail number. Press and hold the 1 on your device’s dial pad to call and connect to your voicemail. Press the star * key to access the main menu. Press 4 to access the mailbox options. Press 7 to change the language of the voicemail prompts to either Spanish or English.