I’m sorry this happened to you. It seems to be common practice now with these third party sites. They used to be such reliable and good companies. And it’s super frustrating because it’s often the only booking tool available, especially for certain hotels for some reason. They know what they’re doing and they just keep getting away with it. When someone does get something to stick its nothing compared to the immense theft daily that they’re partaking in.
I once booked an overseas flight through booking.com years ago now. I got an email from them telling me it was time to check in to my flight. So I went to the airline’s site. The airline had no record of my ticket. Said booking reserved it but never finalized the ticket so I had nothing with them. Booking refused to fix the problem and refund. I spent months fighting with them. They never made good on it and their own customer service people basically said they’re a scam site now and they pull this crap and never make good on it with people all the time. They have tons of lawsuits against them that go nowhere. Lawyers don’t want to touch it. DONT EVER USE THEM. You’re asking for trouble. I only book directly with airlines now. I use the big sites as a search engine but then book directly with the companies even if it’s a little more cost. It’s worth the peace of mind.