It is possible that someone else tried to register (but could not activate) an user account with your e-mail address. To recover the user account registered under your email address, please use the “forgot password” link in the application and an email will be send to your e-mail address to reconfigure the password so that you have access to the user account registered under you email.
It is adviced to remove the user account via the application first before using the user account (it could be that wrong customer data was entered). Removing the user account can be done by logging in to the application and select “my account”, then remove user account. You will need to reregister your account after this action.