Payment reversals will go through a payment gateway, provided a gateway is configured.
Recorded (offline) payments which have not yet been issued to an invoice cannot be reversed, they can be deleted however.
Under the Payments heading on the left select the payment you wish to reverse
Under the same Payments heading click the icon
On the Reverse Payment pop-up specify the Date and Posting Date of the reversal and if desired the Detail field and then click Reverse
The reversal for the full amount previously paid will now appear in the Payments list and disbursements that were applied by the payment will be removed