I agree with Dick here - if Airservices has a serious safety deficiency but CASA is taking no action there is something seriously wrong.
But Air Traffic Controllers, being the professionals that they are, would surely be officially reporting such serious safety allegations - especially if they are regularly happening and are real. If the reports are routinely being ignored then these safety breaches should be reported, in writing, to someone further up the "chain".
Of course, there might be a problem if ATC's consider something a safety problem but the Safety Managers and CASA don't. Then somebody is obviously wrong or wrongly informed or mistaken. Either way it is up to the employees of an organisation to report serious safety breaches....is this actually happening or are people just having a complain.