If the new property management company for my building is unethical and abusive, what can tenants do?

A new property management company took over in March at my building and have proven to be difficult to work with, denied the existence of mold (just painted over it), and have attempted to evict at least one tenant using falsified rental agreement documents. They have inaccurate records claiming rent owed from years ago and are trying to evict people based on those records, even though California Code says they have 12-months to take action. What recourse do we have? They are unresponsive to issues in the apartments such as AC not functioning properly. Suggestions?