The Australian Competition and Consumer Commission (ACCC) has released a number of free resources outlining the rights and obligations of consumers and providers in the emerging disability marketplace. When you pay for a product or service yourself, as an NDIS participant, or through your state or territory's disability support system - you have consumer rights.
Australia's consumer protection agencies have produced a range of educational materials to help you understand your consumer rights and to help you use these rights if something you pay for isn't right. You can view these guides and resources free online at http://www.accc.gov.au/about-us/information-for/consumers-with-disability.