Thank you, MKSKS... I followed your directions and contacted both PayPal and my bank.
PayPal support said, they cannot refund my money because it's friends and family transaction, but PayPal likely hold/freeze sellers account.
And I also contacted my bank to dispute, and bank will see what they can do and will let me know the outcome within few weeks.
If I won the dispute and got money back, that's good... but, my intention is to freeze seller's account so he can't scamming people again.
Is anybody who bought this method, able to get a refund?