The Property Manager is the employee of the owners, including your landlord. As part of his duty to the owners of your unit, he should be relaying your concern to them. If he is also the letting agent – which is often the case – you have one of these clear conflicts of interest where he is supposed to be reporting your complaint, which may be about him, to the owner so that the owner can complain about him to the EC (which is more likely than not controlled by him too).
This is why long-term caretaker contracts are one of the most profound corruptions of the allegedly democratic system of strata living.
In your case, if you are getting nowhere with issues, deal directly with the owner or go to Fair Trading (Tel 13 32 20). You will also find lots of good advice on the Tenants NSW website.