That is certainly not a problem, because when you place an order online, an account is automatically created. This is because without an account, we cannot allow an order to proceed in our system.
Go to 'Login' at the top right of the website and enter the e-mail address where you received our communication. You will receive an e-mail to reset your password (also check your spam). You can then use this password to log in to the website. The return can then be registered and you will receive a free return label in your mailbox.