I got scammed on Swappa about six months ago. I was buying a used Google Pixel tablet in "mint" condition. It was really used and terribly scratched up.

Swappa staff were unhelpful and only after I opened a dispute with Paypal did I get my money back.

I don't blame Swappa for a random dodgy seller, but this was an "Enterprise" seller, whom is still selling on Swappa today!

See this reddit review, which isn't mine, but is almost exactly what I dealt with.

https://reddit.com/r/Scams/comments/1d8emzf/suckered_on_swap...

Reading OP's post, I can't help but wonder if they bought a Verizon Pixel. This is a very very well-known gotcha. Verizon locks their bootloaders and you can't bootloader-unlock Verizon Pixels, even after they are carrier-unlocked.