It’s important to give Nissan (or any other manufacturer) the opportunity to put things right. While ever that process is ongoing, you need to be patient and allow Nissan to try to find a fix. Your car is still covered by the manufacturer’s new-car warranty, so that’s the process by which it should be tackled. If Nissan were to give up on the problem (and you) then you’d have cause to seek recourse according to Australian Consumer Law. I’d also be talking to Nissan Australia’s customer service division to see what else can be done.