You should probably get the non-emergency number for your town's police department, if you don't have it already, of course.
And use it when this crap happens--
Actually, no, that's kinda sneaky as it goes around your parents. I would probably just tell your parents that it happened again (evidence if needed), and have them take care of it. If they don't then call the non-emergency number for the police and have them take care of it next time.
I'm sorry that you have to deal with this.