“Hello! You’ve reached the voicemail of [your name], [your job title]. I’m currently either away from my desk or on the other line. Please leave your name, telephone number, and a short message after the beep, and I’ll be sure to get back to you as soon as I’m available.” Press and hold the 1 key to access the voicemail system. When you hear the recorded message, press the # key to bring you to the system menu. Press 4, for the Personal Options followed by 2 for Personal Greeting. Follow the prompts to record, listen to, re-record and save your greeting. How do I change my voicemail number on Samsung Galaxy s8? Find “Voicemail number” Press Phone. Press the menu icon. Press Settings. Press Voicemail settings. Press Voicemail number. Save voicemail number. Key in +61414121121 and press OK. +61414121121. Return to the home screen. Press the Home key to return to the home screen. Dial voicemail: Press and then hold on the envelope icon displayed on the main screen. Enter Your Accounts Password: Enter the password if prompted. Delete voicemail: Tap 7 on any voicemail and it will be deleted successfully. Open the dial pad on the device. Open the application drawer and scroll through to find the Phone app. Dial Voicemail. Tapping the number 1 and then hitting the green phone icon at the bottom should call Voicemail. Enter a password (if there is one). Skip through messages. Delete a voicemail. Log into Google Voice. Click on the gear icon. Select “Settings” from the menu options. Click the “Voicemail & Text” button. Click “Record New Greeting” in the Voicemail Greeting section. Enter the name for the greeting you are going to record. Select forwarding phones. Click “Connect.”
Is there any way to retrieve the voicemail greeting from a smart phone after the service has been stopped to the phone?

Personally, I think Samsung has one of the best ways of dealing with your voicemail. In addition to offering a quick and easy way of acessing your voicemail, Visual Voicemail will let you jump right into the message you want to listen without having to listen to each message until you get there.
If resetting your Networks Settings doesn't work, the Apple forums suggest enabling Airplane mode for 30 seconds to return to Visual Voicemail. I have personally experienced the "Call Voicemail" issue every time I have updated to the newest iOS 11 beta and reboot my phone. After two attempts, the Airplane suggestion worked and returned my Voicemail back to normal, where I can read a transcript or listen to an individual voicemail directly from my iPhone. Here's how to quickly enable and disable Airplane mode: Swipe up from the bottom of your display anywhere on the Home screen. Tap the airplane icon. Wait 30 seconds then tap the airplane icon again.