I asked cj.com on a merchant with batching process which reversed a sale today with the reason: returned merchandise. I wanted to know how cj.com makes shure that the merchandise is really returned and the sale amount is paid back to the customer. They answered the following:
"We leave correspondence about specific transactions to the advertiser and publisher. There is not a way for us to find out if the merchandise was returned, we trust the advertiser to only reverse a transaction for legitimate reasons."
I can't believe that cj.com is out of any controle of that.