You can create a credit memo, provided an invoice has been created.
This action will update the transaction in Trust Payments system. Please follow the steps below:
When an invoice has been generated, on the Order detail page, click the "Invoices" tab in "Order View" section.
After that, select the invoice you want to refund.
When the invoice detail page is shown, click "Credit Memo" on the action bar.
You will be redirected to a new credit memo page. Scroll down to the "Refund Totals" section. Enter the Adjustment Fee if performing a Partial Refund, otherwise leave as 0 if you need to perform a full refund. To process a refund, you must click the “Refund” button and NOT the “Refund Offline” button, as this transaction will not be processed through the gateway and will not be settled.
Once a refund has been performed, a note is added to the order in the "Comment" section. To view the note, access the Order detail page, and scroll down to the “Comment” section.
If the transaction has not yet been settled, it will be cancelled instead of being refunded, after which a comment will be added to order ("We voided the transaction because it has not settled yet").