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.
Apr 27, 2013 · If the caller needs to a have longer conversation, then they should schedule a meeting or a coffee and have the conversation face to face. Or plan a conference call. Let the phone ring at least 6 times (or until the jump to voicemail occurs). This gives the receiver time to put down what they are doing and come to the phone.

If you have a call forwarding set up, it is likely to cause conflicts with voicemail. To turn off Call Forwarding or make sure it is not enabled:
Of the many things your phone can do, automatically recording a phone call is not one of them. Perhaps not including that feature is a security precaution for phone makers; it could be a potential liability issue. Regardless, from time to time, documenting a call is a useful thing to do, whether you’re conducting a phone interview or cataloging a customer service call.