Visual Voice Mail on ATT BYOP iPhone 7 Plus

Has anyone actually managed to fix this issue? ST support is less than helpful, telling me to "check my iPhone manual"
https://straighttalkwirelessforum.com/
https://straighttalkwirelessforum.com/viewtopic.php?f=6803&t=1285487
ST - Mark wrote:Hi infinitewill. My name is Straight Talk Mark. We apologize for the inconvenience. To further assist you, please check your forum inbox for a message. Click on "New Messages" beside User Control Panel to view your forum inbox. You may also text the key word HELP to 611611 to view our self-service menu with a list of help key words with valuable information. Thanks.