You may have enabled 'Pre-Authorized' payments with the card system you have integrated with Spoonfed.
This enables a Customer to provide their card details in a secure way and you can Charge the card at a later date, such as the delivery date. Card authorizations only last for 30 days, after which point payment cannot be taken and another authorization must be made.
Occasionally after an Order has been confirmed, and the payment has been authorized by the Customer, they will request that the Order is amended in some way. More often than not this will result in the Order Value increasing or decreasing.
If the value of the Order has increased, you will need to 'Reconfirm' the Order in the Back Office, and send a new Payment Request Email to the Customer.
In that email will be a link for the Customer to re-enter their card details. This is to authorize payment for the difference between the current Order value and the previous.
Thus, the Customer authorizes the initial amount and subsequently a second payment for the amount in which the Order increased.
If the value of the Order has decreased, there is no need to obtain a fresh authorization from the Customer for the payment.
The Customer has already authorized the amount and should the value decrease, your card system will only charge the Customer for the current Order amount.