To help your organization retain both customers and funds when cancelling registrations, you can now select to refund a cancelled order to a credit balance belong to the customer.
The customer can then spend the credit balance on future registrations or purchases associated with the same remittance account. 
After the refund is issued as credit balance, your event team can also issue it back to customer's credit card if they prefer to receive a refund.

Please check following instructions of credit balance workflows: Beside issuing refund as credit balance, your event team can also adding a credit balance to a customer with an expiration date, please check how it works: