automatically send unknown caller id to voicemail
Anyone know of a way to send unknown caller ID calls automatically to voicemail. I'm getting multiple calls per day from an "unknown" caller ID with no associated information (i.e., I can't block these calls with any of the supplied Apple phone tools). "Do Not Disturb" also does not solve my issue (if it could block all calls with missing caller ID information, it would be the perfect solution).
Surely there is an app out there to do this...
iPhone 6s, iOS 9.2.1