I've reset it, cleared the wearable cache, even have the voicemail notification disabled in the wearable app but it won't go away. This is the second time it's happened, the first time a factory reset cleared it, but not this time
On the watch itself I go to Settings--->Permissions and call, user history, and contacts are all enabled. I also go to settings----->call---->voicemail and the only thing there is the voicemail #. If I tap the phone icon I get my call log which I can delete.
On the phone itself I've gone to Settings---->Apps---->Wearable. From there I can and have cleared the cache. Additionally in the wearable app on my phone I've gone into notifications and turned off voice. What is odd is the VM notification I get on my watch is in red. The icon in the wearable app is green. If I open the wearable app on my ohone, go to apps, I select phone and the only options are uninstall and force stop (which I've done)
Have you contacted your service provider to see if maybe the notification is stuck within the network. They should have the option to refresh your account which would clear the notification.