I bought a new laptop on Amazon.com.au but sold and sent by Amazon US. This 1st laptop had issue (reboot, freeze, etc.)
Amazon couldn't fix and replace it "as it was from the US". They eventually gave me a refund to buy another one.
I received the 2nd laptop. It is not new, it is a used product returned: "warehouse deals, verified and repackaged".
I have now the same issue the 2nd laptop, it was sold by Amazon US and needs to be returned to the US address.
This is a mess, and I am stuck with Amazon.com.au due to gift-card which can't be used anywhere else.
So please be aware that any product bought on Amazon.com.au from US Amazon will be regarded as it was sold on Amazon.com. You have no local, Australian warranty on those products.
That is awful of AmazonAU to send out a refurbished item in lieu of a new one. This is a not lawful nor in good form.
The first instance is a bit of a grey area as some items have regional distributorship agreements, making your first laptop a grey import.
The laws on grey imports are grey. Having said that, flat out refusing to take the laptop back to send to manufacturer at your cost is also unlawful.