Pay monthly: intro to interest free credit

• Our payment provider is Klarna – who are they?
• What do I need to be able to make a purchase with Klarna's Pay in 3 Instalments?
• How can I increase my chances of being accepted for Klarna's Pay in 3 Instalments?
• I’ve cancelled my order. How long will it take to receive a refund and how will I be refunded?
• My personal information: is it safe with Klarna and can I update it?