I have done all that is prescribed here...many times, and still have no visual voicemail transcription.
I spent almost two hours at my local Verizon store with a rep (who...along with 4 others there HAD iOS11 & HAD visual voicemail) and on the phone with VZW tech support, and finally with Apple tech support. I left the store frustrated and angry, because nothing worked.
I came home and called the Apple tech ("Meagan") who hung on the phone with me as I did another complete clean install of iOS11 and tried to make things work, thinking maybe I had inherited a corrupt file in my OTA update originally.
After all that...still no visual voicemail!!!!!
So, Meagan asked me to wait 24-hours and call her back so that she and the other on-staff Apple tech geeks can ponder about the problem and record this as an issue.
Great.
In the meantime, I feel like I am the only guy who can't seem to get a feature of my phone that I counted on the help me scan quickly through the 50-60 voicemails I get a day. I'm very, very disappointed to say the very least. I have always counted on Apple and have never had one of the weird "glitches" I read about until now. Ugh!