Like pay up now or really pay up later type threats. LOL How do you know they will not do more damage if they come on to or into your property? I am thinking something that is not easily identified at first but causes problems later? Like watered down pesticide or just plain water/no pesticide? So that way you end up with no protection but don’t know it till down the road?
I suggest calling the state licensing board for your state and/or your state’s consumer protection board and let them know what is going on. They made be able to intercede and get you some relief. I would also start taking down names of everyone I talk to in person/phone and anyone who steps on my property. Their paper work should have some sort of state license number. Do they even have a current license?