The telemarketer had no business with you and obviously dialed the wrong number by accident. Therefore I see no reason for you to rudely hang up on them without first letting them know they have the wrong "entity", unless you think "abruptly" is how all people including you should be treated upon making a simple mistake.
FYI, geniuses: If you're smart and let caller know they have the wrong number, they won't call back 5 seconds later trying to re-check that they haven't mis dialed.
I'm glad you reported it because my phone just rang and this number showed up. Just a few minutes before that a call from 123-456-7890 called and it's getting really annoying.