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.
2. Professional voicemail greetings for your business cell phone number. It’s a good practice for each of your team members to have their own personal business phone numbers.

You may need the password you created when you set up your voice mailbox. You'll only need to enter your password in the Visual Voicemail app once, during the initial setup of the service. To limit unauthorized access to your voicemail, consider locking your phone when you aren't using it.
I got a new cell phone recently. As the world stood in line to pick up the latest iPhone 8, I graduated to the 6S. I pride myself on that actually. As with all new phones in the 21st century, the voicemail must be set up anew. I used the default message for the first few days, but finally settled down to record a more personal greeting.