This is all very sad. It is a 5 USD plugin of which the developer receives 4.52.
Or it does not receive them, that is the question.
The customer is from Germany, not from an underdeveloped country and this is the equivalent price of one or two coffees in that country.
It is the habit of underestimating the work of developers and being happy to have found a way to have a plugin without paying for it. It feels like a triumph: "How clever I am, I already have the code and I haven't paid."
OxWall does not provide any tool to block this user from continuing to purchase plugins and then not paying for them.
PayPal also does not provide this service and in case of dispute it always resolves in favor of the buyer.
I am going to modify the https://owspain.com store in such a way that you pay the seller for one of the payment methods that he provides and it is the seller who assigns you a license so that you can download the product when there is received the money. End "instant downloads" without paying.
To the developers I remind you that the owspain.com rules allow you to implement your own forms of payment, licenses and websites to download the products, and that is why you can only put advertising.
The goal of owspain is to keep the community alive, not to make money.