Sky Phonez on Kogan Marketplace Sold A Used iPhone X as Brand New

I bought an iPhone form a marketplace seller "Sky Phonez" on Kogan last October. I know it sounds very fishy instantly, but I was looking to buy an iPhone X as brand new in late 2020, and there's not much for sale (turns out there're probably none).

Reason for a retired model? Well iPhone X seems to have all the equipment I need but no less — good screen, good camera, decent chip for a couple more years of software support, and the specs are not that bad even compared to the later models except for the claimed "newer generation chips".

So I thought I can get a decent phone on a decent price so that I can pretend that I'm smart, and that's how I became stupid. I found this guy on Kogan listing "Apple iPhone X 64GB (Brand New)- Silver" for 800 bucks. Bought it, my wife has been using it, found annoying camera shutter noice cannot be switched off and always lagging on map navigation, probably faulty GPS, but generally alright to use. Then she upgraded her phone just then, and I gotta upgrade to this iPhone X from my old SE first gen. I took a closer look, and found something wrong.

Warranty has expired. New iPhones always come with one year Apple warranty, but this one expired within a year. I double checked online and got the same result. So I know this is much likely a USED phone.

I contacted the seller, got no response. I put forward a dispute to Kogan and pointed out the fraudulent false advertising. However they got back at me and said they're sorry for a "listing error".

I'm not sure how far I can get from this, but I want to post this out and raise awareness. Probably very few of you are ignorant like me. I'd appreciate if someone can suggest what I can do to claim back my loss.

Also I've got an Apple genius problem here. Not related to the above case though. After I restored my backup on the iPhone X, somehow I can't purchase or download any Apps, and most photo has disappeared and not syncing from iCloud. If anyone knows how to fixed this that'll be great.