legal or not

I have been living in my current apartment for three months. The apartment has wood floor and it is not soundproof. The guy living upstairs makes noises every night. I have reported this issue to the apartment management office many times but it has not been resolved. I just sent a letter to the manager and told him that I would not pay the rent until he get it resolved or exchange another apartment for me. Does anybody know the law about apartment leasing? What I am doing is legal or not?

Thanks for you advice!