How do I say "If you call your parents, I better not hear you tell them I did anything wrong" without sounding like an asshole?

I have a lot of kids who if they get their feelings hurt, they call their parents and proceed to tell them that I'm the devil "who treats them badly". Then I always get called and asked why I treated their kid so poorly. I've had CPS called on me. I've been threatened about my job over parents. I finally just tell all my classes "If you ever call your parents because you're upset, I better overhear you telling them that you did exactly what you did and you chose your consequence. If I hear you telling them that I am "mean" or I "treat you badly" I will simply hang up and tell them that. And if you don't want me to answer, don't call me on the school phone.<br><br>Kids call home a lot because I have second graders and many have anxiety that they were separated from their parents at school. I always allow children to call home and to talk to them. I simply don't want parents to ask me why I was so mean to their kid because their kid didn't want to do their work and chose not to have recess, but I still let them play with a game.