how to block calls from callers not in Contacts?
To stop the robocall, is there a way to just block calls from anyone whose number is not in your Contacts? Unknown callers could be sent to voicemai. I tried multiple call blocker 3rd party apps (NoMoRobo) with poor results...maybe catching 1 in 8. If not, why not? This robocall thing is getting out of hand as I receive 2 dozen daily.
iPhone 8 Plus, iOS 12.1