How do I cancel a deal that was paid through the app and closed?
Closed deals can only be cancelled by the customer. Once the customer cancels the deal you will receive back the commission you paid and the customer will be deducted the DealCoins he/she earned with the deal, but you will have to transfer back to the customer the DealCoins you received for the deal.
If the deal was paid through the app you have received the payment in DealCoins. You can send a transfer to the customer for the amount you received for the deal or you can refund the customer as you both agree.