Your account has been blocked for security reasons due to there being multiple failed attempts to reset your password. This is nothing to worry about and is simply to protect your security.
Once 24 hours has passed you will then be able to reset your password onsite by clicking on 'Forgotten Details?' from the Home Page.
You will need to enter your registered email address and date of birth and you will then receive an email with instructions on how to reset your password. Once you have done this you will be able to login to your account again.