Have a look at this factsheet HERE on the Tenants NSW website. It includes a letter you need to send to the landlord outlining the work that needs to be done and their agreement to do it. It seems to say that the landlord can't hang on to your deposit if they have promised to do the repairs but then doesn't do them. The fact sheet also has contact details for the Tenants Advice and Advisory Service (you fill in your postcode and it directs you to your local office). You should call them before doing anything else.