You are quite right to complain to the managing agent. The tenants are required to adhere to the bylaws, a copy of which they get with their lease.
looks like you need your Owners Corporation to issue a breach of bylaw. The bylaw you are looking for concerns causing a nuisance.
Dont be put off if the OC is lazy in issuing this for any reason . You have a genuine grievance and the OC needs to act.