enterprise employees dumping trash in my backyard 😐

so there is a car rental next to my house. there is a bunch of trees and bushes and a ditch in between us, but the ditch and the trees are on my property. I have been over there twice already to ask them to get the trash up. they didn't, and now there is more. it looks disgusting and that ditch is to help prevent flooding, so whoever is doing it is a lazy idiot. I'm just not sure if I should just ask again or can I ask a cop to speak with them or something? I'm just sick of dealing with this. don't they have garbage cans?!? and yes, everytime I go over I ask to speak to a manager. I don't just bitch out the person at the front desk lol.