Thanks for your help to tell me "The financial ombudsman". However, I still want the case can be solved by PayPal decision maker.

As an eBay seller, I hope eBay can review their "on buyer's side policies". Or at least give eBay seller a rights to pre-block those kind of buyers to create a fair trading place.

Some of those buyers normally do same things to other sellers, and you can found some of bad buyers always left negative feedbacks to eBay sellers, but their feedback score is 100%.

Who knows when they will visit your shop?