To cancel a refund, you must call the API method refund. A refund can be cancelled if, and only if, its status is requested (RE) or pending (PE).
To understand how it works, look the refund flow in the following diagram:
The merchant can cancel the refund through the Dashboard or the API. If everything goes well the refund will be immediately cancelled.
If a refund is cancelled, the customer will not receive the money and the merchant will not be charged. Customers are NOT notified about the refund cancellation.
A successful request will return a JSON expression similar to the one below.