What eventually worked is going into my deleted voicemails and pushing "Clear All".
Android phones can access voicemail by holding down the 1 key on the dial pad until the phone dials your 10-digit phone number. You will automatically connect to your mailbox and be prompted to enter your temporary password; this password is the last 4 digits of your phone number followed by the # key. Start the Google Voice app. Tap the three horizontal lines at the top left of the screen (sometimes called a hamburger menu), and then tap “Settings.” In the Voicemail section, tap “Voicemail greeting.” Tap “Record a greeting.” How do I access my voicemail? To call your voicemail on an Android phone, simply open your phone’s dial pad and hold your finger down on the “1” key. You can also call your voicemail from a different phone by calling your own number and tapping the pound key. How do you check your voicemail?

We cannot promise the exact time frame at the moment but we are looking at Q4 2016 to add a lot more features as well as improving our coverage map with more ground. At the moment our primary target is to improve our coverage.
Step 3. You will be asked to create a voicemail password. Create a password and then tap “Done”