Charities that ring and ask for someone who isn't present, and when so informed breezily reply that they will try again another time.
Knock knock, people. I don't want you to try another time. I am almost always the one who answers the phone and I don't want to keep being annoyed by these silly calls. If you can't leave a message and a number for callback like a normal business, you shouldn't be ringing people in the first place.
Yes, it is a land line (sort of, it's RBI). No, we do not use cell phones. That is not an invitation to keep interrupting whatever we are doing at your convenience instead of letting us contact you at our convenience. If you can't work that one out, then get stuffed.