There’s always the nuclear option. Just tell them to get off your fucking porch as you slowly walk towards them in an implicitly menacing fashion. (But don’t say anything explicitly threatening).
Then watch them shit their pants and run away with their tails between their wobbly legs.
Again, do NOT lose control or say anything explicitly threatening. Three times people lost their shit on me when I was a JW and I turned around as I was leaving and shut them down. I even called the police on one of them. They blew it with the explicit threat. (Probably they’d been fucked over by this cult, who knows. They were so angry they couldn’t even talk.)
But if anyone would have down what I advised above even I would have left post haste.
Intimidate but never threaten. Never.