Most landline junk calls have a long pause activated by repeated “hello”s from the unfortunate recipient.
Here’s what I do:
Phone rings.
“Hello, ______s”
Silence.
“3 - 2 - 1 - GOODBYE”
if I’m in a good mood.
Otherwise it is
“3 - 2 - 1 - FU”
(not abbreviated)
Get them on the line and say, “ wait a minute someone’s at the door” and set the phone on the table. As long as your end is open, they can’t hangup. Slows their calls down.
Or my favorite, state talking in spanish