Returning tracks! I'm bombed

Hello. Today came a return from the buyer. He bought the track on April 25, 2018 and today returned it. But he returned this day not only to me, but also to several people and not one track. I have every reason to think that he is a fraud or used stolen cards. He laundered money.
Question to Envato! Can make some sort of framework and restrictions on the terms of return.
How to avoid such buyers? How Enwato controls these returns. On what grounds do they return them? I’m bombed by this situation …

Got reversal a week ago from purchase made 2 months ago by buyer from US. It’s my third time got reversals, and surely Envato have done all the things they could.
It’s a hole on digital transactions nowadays. Not just on Envato, but everywhere, even on eBay.