Currently a Tip made on an integrated Tyro terminal is recorded in Bustle so that you can balance your tills at the end of the day, however the ability to refund a Tip is a little more tricky.
As the Tip was made in Tyro and not Bustle, there is no transaction or stock movement (as such) recorded in Bustle to then refund.
So if you do need to refund the Tip amount we would recommend processing the refund manually on your Tyro Terminal.
Please note: This will result in a variation between Card totals when you complete cash up. You will be up on Card for the day to the total you refunded.