I recently purchased a LG G4 mobile phone which arrived this week and it looks like the phone is sim or network locked as it is not recognising any sim card. I have sent contacted them via eBay but they seem to only answer you if you buy something. I understand they have an office in Sydney somewhere so I'm thinking of rocking up there and shaking things up a little bit.
You can contact Quality Deals from their eBay user page. You don't need to purchase an item to contact them. However if they don't seem to answer your inquiries on eBay, they might not reply your emails either.
Anyway they have registered the domain quality-deals.com.au. You would be able to find ABN (from WHOIS) and track down more details with that information (ABR/ASIC search) however we don't allow posting personal information here.
If they're not answering you, and you payed with PayPal, just open a dispute.
try sending a PM to andyman:
https://www.ozbargain.com.au/node/206289#comment-2963213