In order to refund a credit card charge, you will want to navigate to the Billing tab within the menu bar or within the specific client's profile. 

If searching for the transaction within the main Billing tab, you'll first want to enter the date range for when the transaction was processed. You can then narrow down the list of transactions further by selecting the specific professional and/or the client for whom the transaction was made. 

All credit card payments will have Payment (Credit Card) listed as their status. Once you've found the desired transaction that you'd like to refund, scroll to the far right-hand side of the screen and click on the "Actions" button within that transaction's row. You'll then click the Delete button which will generate a pop up window asking you to confirm that you would like to void the specified credit card payment (screenshot below). 

If the payment has yet to be processed, you will receive the following pop up message.

In this case, you will simply want to try again in another couple of days once the payment has posted. 

Please note: the timeline for when the payment will process is at the discretion of both PaySimple and the bank from which the payment was made. For any further information regarding when you'll be able to initiate the refund, please have the client reach out to their bank directly.