If you can stand strong then you can move out easily and receive back your deposit and the last month's rent. Just tell them strongly that you cannot resist the mice and the loud noise and want to move out instantly. And also tell them that you will take legal action if you are not allowed to leave. You can sue in the county stating that you are having hard time because of mice and the noise. There was similar case near my apt. They had bed bug problem and they broke the contract stating that problem and got their deposit back.