To process a return on an invoice paid by integrated CC processing, simply go to Accounting, Invoices. Locate the invoice in question. Click the "Returns" Button. 

The Return/Refund invoice will open. Any line items from that invoice that was paid will be showing. Each will have a Quantity of ZERO. Determine how much of what item you need to refund and modify the quantity (QTY) field. 

In this example, there was only one day of boarding charged. I'm refunding the entire day so I change QTY from 0 to 1 and you can see the values adjust in the lower right. (Since my charge had tax applied, it shows in refund as well.)

When it looks proper, click the "Issue Refund" button. It will open the "Refund" window. Choose your payment method. (In this case, we're applying it back to the CC.) Click either Process Now or if customer has CC on file they want to use, click "Retrieve Stored Credit Card" and then choose the card. 

In the screen shot above we chose "Process Now." The CC device will enable and you or customer must insert the card and confirm the refund amount. When confirmed, it will process and approve. 

Again, in KC you'll be prompted to print or cancel receipt if that option is enabled and the status will show "Approved". 

The refund is now complete and you can close all windows. 

*Notes

A refund can be issued back to any card the customer would like you to issue it to regardless of what card they used to make the original payment. You may of course do a cash or other payment method refund as well. 

If the customer whom you are issuing a refund to has a stored credit card on file, instead of clicking Process Now, you can choose "Retrieve Stored Credit Card' and then choose a stored card to send the refund to.