In the case a registrant is unable to attend and needs to be moved to a different Event, you do not need to cancel the registration, but “move” the registration to the new Event.
To move a registration, select the Event and in the Event Details page, select the customer you are trying to refund under Registration List
Once the Registration Details page, go to More Options > Move.
In the following page, select the new Event to move the registrant to.