I wait, talk to the human, and help them to realize they have the worstest job in the world. Then I add them to my cell phone, but mark the SEND DIRECTLY TO VOICEMAIL box. A few choice words describing her [***] helps too.
Yup I just got a call too and no message was left. There must be a way to report this systemic abuse of people's phone numbers? At least with spam email they often give you a way to unsubscribe from a particular sender -why can't they do similar with specific phone callers?