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 help@usmobile.com since there is a verification process involved so we won’t be able to resolve it here.
1. Open your Android’s Phone app. It usually looks like a phone receiver at the bottom of the home screen.

You can tap on Record to start recording a new iPhone voicemail greeting and then Stop when you are done. Tap on Play to listen to it so you don’t have an embarrassing mistake or noise in it. When you are satisfied with the message, tap Save in the upper right.
That way you'll get to know exactly what other people hear when they call your phone and one last thing I wanted to show you. If you don't see that play on record option on the bottom, you don't have visual voicemail. Set up on your phone and that's through your provider. So if you have at and T sprint T-Mobile or any other provider, you need to have visual voicemail.