In your appeals, have you stated that the chargebacks were done in error and that you would like to repay them? As well to be clear, your brother in law closed the credit card entirely and is unable to issue a reverse chargeback? Has he tried calling the issuing back to see if they can issue a reverse chargeback in some way?
And yes, entirely closed and unable to issue a reverse chargeback. As far as I know, he's done all he can with his card account. I'm still trying to get him to contact his bank again, but I think it's a long shot