A hack someone introduced me to that I cannot recommend enough if you still, for some God-unfortunate reason, have a landline: Record the audio for the "We're

A hack someone introduced me to that I cannot recommend enough if you still, for some God-unfortunate reason, have a landline: Record the audio for the "We're sorry, this number has been disconnected" message from Verizon or whoever. Keep it on your phone. If you get a lot of telemarketers, queue it up before you answer an unknown number. Hit 'em with it if it sounds like a robocall. Robocalls still cost time even if they're functionally free money-wise, so a lot of systems will key on that message and will yank your number off their call list.