In case of a higher purchase amount
You must cancel the One-time card service then create a new card for the correct amount.

In case of a lower purchase amount
No worries – you’ll only be billed for what you end up using. When you are sure your entire order has been processed, 

If you don’t select the option in the app, Klarna will automatically adjust the plan after 14 days. If you have already paid more than what you used, 

Good to know:  The authorisation hold placed on your payment card will be released. This can take between 1 to 7 days depending on your bank.

• What is a One-time card and how does it work?

• What if I never use the One-time card service and want to cancel it?

• Why was the One-time card purchase declined?

• How long do refunds take?