The rule
There is no automatic refund for a change of mind. If an event is cancelled, paid orders are refunded in full automatically.
Refund requests
Customers can open a refund request from their ticket; it reaches you by email and appears on the event's Orders tab. If you approve, the order is refunded in full; if you reject, you write your reason.
Manual refunds
You can refund an order directly from the Orders tab. Refunding an order whose tickets were transferred to someone else also invalidates those tickets; the panel warns you about this.
Cash at the door
Cash sales at the door can't receive refund requests. If needed, the sale is voided with a reason from the POS history and the money is handed back.