Refund - Account hacked?

A member of envato market ordered my item of $30. About 30 minutes later, the same account requested for a refund that the item was bought by another person. In his statement, he said the person hacked his envato account and used his credit card to order it.

Now, I have 4 problems with this.
First, envato authority already refunded the money to him without my consent.
Secondly, The item has been downloaded successfully [ removed by mod, let’s not advertise more than needed ]
Thirdly, the said account seems to be deactivated now.
Lastly, how was it possible for his envato account to get compromised, because I believe this site is safe.

I don’t think I believe his story enough. Please help look into this as I’m a new author here. This seems strange to me and also presses a bad impression already after just 2 sales :).

Regards.