In my household we don't just get mad a telemarketers, we get even! That's what the Jolly Roger Telephone Company does by setting them up with "pirate" bots that waste their time. If you like Shark Tank, please check out The Jolly Roger Telephone Company. They'll be on there tonight (10 March 2019). https://jollyrogertelephone.com/ 
Alright! They didn't cut any deals with the sharks, but they kept control of their company and got some awesome national-level publicity!