Called again - only one ring - nomo robo took care of the rest

Today it was Rachel calling with an offer to lower my credit card rate. I have told them that I do not have any credit cards and have asked them to stop calling me. Once you get a live person and tell them the above, they just hang up on you.
Yesterday I was able to speak to Frank and tell him the deal and then hang up in his face. Unfortunatley they will just
continue to call, if not from the above number any number they can use.

It was the usual recorded message from scammers offering to lower the interest rates on credit cards.  If we can't even stop these criminals, who probably make thousands of robocalls every hour, how can we "degrade and destroy ISIS"

Called and once answered, no one on the line.

This # called me on Sept. 17 at 215 PM. It never left a message.  
Just crazy!   To me if it's important, the caller should leave a message.  & yes, I did again within a week ago put both my land line & cell # on the do not call registry.  I usually do this 2 times a year when I seem to start getting calls that never leave a message.   Now days I'm afraid to pick up the phone because it just might be one that if you answer it you are charged lots of money for picking up the phone.