That's for purchases, not for your paycheck.I suppose if you earn money through PayPal, someone could theoretically ask for it back, but as a service vendor through PP, you are allowed to create a non-refundable clause in your contract, which you cannot do here (to my knowledge, IDK).
Can you imagine working a "regular" job and having your boss say, "Yeah, um, we might be taking back your check from three months ago. We'll leave you hanging for a week or so and then let you know what else you can do for us so you can keep the money." ?????
The excuse I hear all the time is "That's freelancing," as if that's supposed to make it all right.