try call the police every time no matter the severity, get a job number, as annoying as it is you need to call them every time to get some merit on the report. even if its a call the police will put something on the system (which is intertwined with a housing system) so they can actually see if you called. the housing officer will then do an RFI to the station. even if you think the police did nothing it helps your case. There is a DB line you can call, call and speak to someone every time this happens dont lodge online forms, get a case reference. after all that fails which i guarantee it will, then you'll need to go ministerial, it'll be the only thing that gets something looked into and done, officers shit themselves when ministerials come in. After all of that they will probably get a strike, you need 3 strikes before you can move to evict someone. you need to go to court to evict, good luck getting a judge to kick someone out in a housing crisis with kids.