It is because of the actor really. Conceptually their strategy is "if they give an inch take a mile and keep on taking" while using every bit to beat them with

It is because of the actor really. Conceptually their strategy is "if they give an inch take a mile and keep on taking" while using every bit to beat them with it over every little petty issue. The way to shut them down is to tell them to take a hike from the start to deny any leverage. Reconsider if they have anything worthy of consideration. Part of effecfive communication is not looking like a bad actor with an approach.