If a customer wishes to cancel an event, they can easily do this (if it has previously been set up) online (see here). However, if the customer has missed the cancellation deadline or does not currently have Internet access, they may contact you.
You can cancel a customer's booking on the check-in page of the event. You can access this, for example, by clicking on the corresponding event in "Events" in the menu. Now click on the "X" next to the participant to cancel it.
Now you can choose whether credits will be credited or not with either a credit pass or a "single event" product (e.g. trial visit)
If the credit is refunded, the customer can take part in an alternative event at a later date.
If the booking is cancelled without a refund, the customer loses a credit on his credit pass or cannot reuse his "single visit" product.