As per terms and conditions, if you wish to make a change to your booking after it has been confirmed, you will have to  pay any additional costs directly to Costa via credit card. Amounts and payment dates of your Klarna instalment plan will not be affected. If the changes to your booking amount to a price that is lower than the original one you paid, we will refund the difference via Klarna. You will find your refund amount directly on your Klarna account.