You have a few options when it comes to refunding a transaction—
1. You can Refund the transaction via POS > Transaction List by selecting Details next to the sale you want to refund.
Then select Refund Transaction:
Doing it this way will keep a record of the original sale as well as show the refund in your Transaction List. You will be able to delete the refund if you need to as well. Check out the following article for more information: Refunding Through the Transaction List.
2. You can also delete the original transaction instead by clicking the red cross next to transaction on the Transaction List: Editing, Deleting, Re-processing & Backdating Transactions
3. You can also process a refund via the POS tab, then choose the Refund tab.
Click Add Client, and search for them on the right side panel to add them to the refund transaction.
Once the client is listed, click Add Items, and use the product, service etc option to add the item(s) to the refund, depending on what you're refunding. Choose the actual product/service from the right side panel and click Save to add it to the refund transaction.
Once you have the item(s) listed under the client name, click Refund Payment, choose the payment type and Finish Refund.
You can check out your Transaction List in POS to see the refund transaction recorded.