pick up and wait for them to say hello then, if you notice a 4s lag then it's the robocall rerouting to either a robot or a live person to initiate the scam.
don't say hello, just pick up. If it's a real person on the other line trying to find you, they'll just say "hello, @bandwagon?", hello?
also, remember don't say "YES", just go "
Bandwagon
here, who dis?"