I wish I had good news.
Do you turn your phone off a lot. Each time your phone is turned off it will tell you you have received a new msg even if you haven't. This voice mail thing is some kind of glitch in the system. Don't know if it's android or Samsung. So yeah, it's a pain.
Hello Chew, I've tried to follow your second option, but it still didn't work for me. So I changed a little bit the part where you select the phone apps, instead, I selected the "call settings" app and then clear the cache and the data as well. This little modification worked for me. Thanks a lot for your sharing.
Clearing the cache could work
If you would like to reduce this notification to almost nothing then i have the best solution to permanently reduce this notification
Inside of the phone app go to settings>voicemail>notifications>and silent and minimize them, this hides the voicemail notification unless you expand the notification panel then it there but minimized
Hi, I've tried all the suggested salutations, and cleaning call data worked.. Until restarting the phone, then the notifications icon was back again. Then I tryed cleaning all phone and call cache and data and then I powered off the phone for 5 minutes. IT WORKED... NO MORE VOICEMAIL NOTIFICATION ICON!