Try using your voicemail and see if the problem still exists. Method 3: Setup Your Visual Voicemail. If you are unable to set up your voicemail through phone settings, then you can try setting it up through your carrier. Voicemail is related to your carrier and it is best to be done this way. This may not work for all kind of carriers.
Depending on which Android phone model you are using, you can dial the carrier code and directly stop the Voicemail service.

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?
A personal voicemail greeting is an easy way to prevent callers from hearing a generic greeting message. It ensures that people know they've reached the correct person, and makes them feel more comfortable leaving a voicemail. To change your voicemail greeting on an iPhone, you'll need to follow a few simple steps.