I found some simple information on Cash refund, hope it help.
Rebate offered by a manufacturer to a consumer. After the consumer has purchased the manufacturer's merchandise, the manufacturer will return a portion of the purchase price in exchange for a label or some other proof of purchase.
Cash refund is the money which is returned to the customer in the form of cash. Cash refund can occur due to a variety of reasons. If a customer has been over-invoiced, the excess amount will be refunded to him. Also, if a product is defective, the company may refund the cash back to the customer for returning the product.