Klarna’s FAQ’s can be found here: https://www.klarna.com/uk/customer-service
Contact Klarna via their live chat function here: https://app.klarna.com/inbox/support
Or by phone:
Local Rate: 020 300 50833
Freephone: 0808 189 3333
COVID-19 related: 0203 005 0834
Fraud related (available 24/7): 0203 005 0837