So, the real question is this - what does Australia have for digital software + digital distribution laws?
This ain't the old days of disc-based DRM - where if you didn't have your disc(s), you couldn't boot + play your games. A lot of PC gaming has gotten away from that.
Even in the mid-to-late 90's, a lot of PC games - you transferred contents from your disc to a hard-drive - which is what EULA's were for. Game-disc checks were often only needed for booting the game-up - and that was it! EULA's were allowing you to make a copy of the game, more or less - so they could let you "patch" it, if need be. See - Discs were static (ROM); hard-drives aren't. Games aren't these static things anymore (since the files are often installed on hard-drives); they are treated like a service, often updated + improved upon. One patch could "fix" a "broken" product. These ain't the Nintendo days!
Digital-distributed software is always going to be this huge gray area on things like refunds, any online-style DRM, online account-based stuff, and things of that nature. When going digital - you can't just go to the store, return your game, and lose access to your game-copy.
That's why DRM is there - it's (supposedly) to regulate who uses the game. Most DRM doesn't really do a great job of that, these days - and well, that's a story for another time entirely.
Software are not physical products like cars anymore! I can take my car back to the dealer - and yep, I no longer have access to the car. Games, that can be a gray matter - as we can back-up games + game-files very easily before we return them. Something like a real car - that'd be hard to copy.
While Steam does have CEG for DRM, some games on Steam underneath it all are actually DRM-FREE - i.e. once you grab the files from Steam, they will work without even Steam installed. For example - Enslaved: Journey to the West is one; and Wizardry 8 is another. If I asked for a refund on one of those games on Steam that are DRM-FREE and I got a refund to get it pulled from my Steam account - then I guess Steam's CEG should force to uninstall it. But, Steam's SSA allows you a different convenience - to allow you to make back-ups. if I already had the game-folder stashed elsewhere for a back-up (in another folder somewhere else, on another HDD, on a BR disc, on some DVD's, etc) - I could still get those files, reinstall them, + run the damn thing w/out using Steam anymore!
I would guess asking for refunds on sites like GOG for my DRM-FREE games - or any other digital site that has games DRM-FREE, for that matter - would be weird, too.
You could get your refund - and never lose your copy of a said game!
Usually, when you get a refund - you're losing your physical product + getting your money back.
In a digital world - that is not always entirely true; it's a gray matter.