Richard,
Sometimes the only way to change things is to hit where it hurts. Some people have hearts and care about the living conditions they collect obscene amounts of money for while others only care about getting the rent on time. So, unfortunately, the only way to get that attention is by hitting them in the pocket. 
I knew several families who sued the State of Alaska over the fact that the State had knowingly licensed a daycare home despite the fact the daycare operator's husband had previously been convicted TWICE for the sexual abuse of young children. As part of the suit they wanted the way daycares were licensed to change so in the future it would not happen again. That was the second most important part of the suit, The first being money to pay for years and years of counseling and treatment for their boys as well as for the rest of their families who were traumatized as well. 
It certainly sounded like the parents tried very hard to get the previous landlord to fix things.