Correct or Cancel Offline Credit Card Payment

If you need to change the date or amount of a credit card payment, you will need to void the original payment via Income -> Payments -> Void Payments.

If it is not feasible to void the original payment, you can make a new payment for the reverse amount of the original on the same date. You can enter the payment as an Other type if needed.  You can then add a new payment with the correct date and amount.