I was TOTALLY wrong.
The scammer issued a chargeback claiming it as "unauthorized purchase".
I sent all the chat logs and the screenshot of the Paypal payment from the buyer and the receipt from Paxful including PGP signature, but I doubt if I will ever win.
Feels so sad that this BS has happened in the end of the year.
I'm stuck between either paying the chargeback or closing my bank account and debit card, never using Paypal again.
I'd used PayPal to convert my Bitcoins and it runs smoothly. Maybe at your part, you'll be having a deal to someone you'd never know and totally a scammer. But that is the only and the last time I'd used PayPal, and I'd never used it again. But hearing this one, I found it more careful for the next deal with.