NSW Fair Trading are only one step under ACL (Australian Consumer Law) Repair, replace, refund, cancel | ACCC and they are mostly toothless when a business refuses to comply. The next step is to go more formal in your approach and write a formal complaint letter to the Dealership and/or Mazda requesting the outcome you want and giving them a reasonable time to respond (14 days would seem reasonable but you may wish to set 21 or 28 days). If they fail to respond favorably then you can apply to the NSW Civil and Administrative Tribunal (NCAT) https://ncat.nsw.gov.au/, for them to make a determination. Warranties are extra rights that businesses offer but the warranties do not replace your rights under Australian Consumer Law, they are additional to those rights.
I strongly suggest you contact some competent legal advice service before proceeding any further, they will be able to guide you and help you prepare your responses. There are free Consumer Legal Services in all States and Territories and we have compiled a list on this site of some of them or you may wish to use a paid service of your choice. The Community list is at Free Legal Advice Centres
The ACCC and CHOICE both provide form letters to help you.
