Following steps will help you in understanding "refund" process:
Step1 - Suppose the admin has got the payment from the customer
Step 2- Admin released the payment to the vendor.
Step 3- Now customer want to cancel the order and want his payment back.
Step 4- Admin need to create a “Credit Memo” for that particular order.
Step 5- After creation of the credit memo from admin panel then go to “CsMarketplace-> Vendor Orders” there is a order grid which will show orders to whom the payment is made and refund.
If on that particular order is showing the refund button click on that enter the fields for the refund made for any orders.
For more details you can visit our demo site: