annoying calls

Hard to understand people calling at all hours including after 9;00 p.m. Calls are anywhere from 3 to four times a day. Very rude will not listen to anything you say. I have asked many times to be taken off their list. You actually have to be rude back and then they hang up on you but that does not stop them from calling back in about 10 min. I don't answer the phone but they will just keep calling? Life is to short to get upset over something like this but I can't help it they just will not stop calling. I have tried calling back the number they are calling from and get a recording, this number has been discontinued. What can a person do ?