If you are seeing this message,  you may have refunded a shopper's purchase (or part of a purchase) in Shopify. ReturnLogic will not allow the refund to go through twice, hence you will receive this message. To Verify, open the order in Shopify.  If the customer was refunded via Shopify, it will look like this: 

There are two refunds on this order. The top one was through Shopify.  The bottom one was processed with RL.  Refunds that are processed through the ReturnLogic platform will look like this:

We're here to help! Email us at support@returnlogic.com or use the live chat inside the platform with any questions or feedback.