By default, disputed transactions can't be refunded anymore. However, in some cases where a dispute has been raised for payment of an order that has not been shipped out yet, the best next step is to cancel the order on your end and update us via email so we can proceed with dispute acceptance.
Dispute acceptance is somewhat similar in processing refunds and it's a win-win situation since the cardholder gets his money back and the merchant gets the item back - without submitting the usual paperwork required in defending a dispute.