Refund Management 
Refunds can be handled automatically in the Administration Interface, once the order has been delivered. Your customers can return the entire order or parts thereof by means of the order splitting mechanism. Every order contains information on the total possible refund value and how much has already been refunded.
All refunds can be listed per order or as a full overview. All sales order items contain the information how much many money can be refunded in total and how much was refunded so far.
See also: