Exprim, sorry to here you problems with paint in the great land down under. There are two guys I know you can help you...Whatyardwork and Steve07, who know paint very well. Another thing you might do is go to the tabs near the top of this webpage and click the SEARCH tab and type keywords like scratch paint
Also may want to look in the SELF HELP TIPS for methods to do the repair. Make sure you use HD paints (usually a layered blend base coat(s) with matte/clearcoat) that must be blended in very carefully.