Received call @ 9:48 this morning.  Caller ID showed 'invalid number'.  Why would anyone think a person would answer such a call!

Called twice today. Of course we didn't answer. Have now blocked the call.

keeps calling does not leave msg. i just dont answer unless I know, but, can't believe nothing much can be done against those harrassing calls!

There can be something done about it, but you've got to be able to let your phone ring with no kind of answer, including voicemail. I found that by outlasting telepests, I slowed the volume way down. If you're required to manually answer all calls, you're going to have a tough time stopping them.