They call say "Hello", I respond with "Hello".
They say "Hello" again, I respond "Hello, may I help you?" They hang up.

Someone from this number keeps calling and never responds when I say hello.  They call often.  Here is some of the times.  These are the times they have called in an hour 1:15, 1:33, 1:55, 2:08 and  2:18

Just received a call from this number.  They asked for me by name.  When asked who is calling, they did not respond.

This number calls me 30+ times DAILY.... No one has ever been on the line and when I have called it back, says it is a non working number... How can that be!!! I AM OVER IT!!!!!!!! It is really getting in the way of my work day!!!!!

Scammers and crooks spoof the numbers you see in your caller ID.  They don't want want you to call them.  Any luck with call blocking?

It really is true that it is best not to answer or call back unknown numbers or suspicious names, and don't let the calls go to voice mail if you can arrange that.  Because the callers keep shifting numbers, the progress will seem very slow at first, but "Ignore and Block" does work.  I went from 3-5 calls a day down to 3-5 a month.  It take consistent application of a system, and some time, but it is possible.