I have just paid three thousand Australian dollars for travel and medical insurance work permit to this travel agency and now they won't another two thousand
Work permits for foreign countries are generally issued by the country in which they will apply, usually through an embassy or consulate office. You would probably be wise not to give any additional money to these folk until you investigate further. If they have, indeed, taken money from you, it might be difficult to get it back, but at least you will not have given them any more.