I don't believe you were to harsh. You did what needed to be done. She wouldn't take no for an answer. Try sitting her down and explain it to her. If she still becomes overbearing about it, turn around and walk away.
I feel sorry for you. Since you have talked to them and nothing has changed, I would start recording it. Im sure the police may talk to them, but they're not willing to change. A recording of several nights, take it to the authorities. Good luck.