What "contract" are you referring to, when you say she is in "breach of the contract"? If she has threatened your life, call the cops and report it. If she has vandalized your vehicle and you can prove it, take her to small claims court--and see if the judge believes you. The police's comment about there having to be a "significant amount of damage" is probably referring to her alleged damaging of your personal property. But if she is making threats to your life, call the cops, and you can also get a restraining order if you really fear her--again, you can go to court to get it and see if the judge grants it. As for the music noise, if it is in violation of the local noise ordinances, call the cops every time she does it. You can also get a local lawyer to send this person a cease and desist letter and see if she stops. The landlord/management company are not the police, but you are entitled to the quiet enjoyment of your living space. The local lawyer can also send a letter to the landlord/management co asking them to do something about it, or ask that you be let out of your lease, but there is no guarantee they will comply.