click here and login using the domain name benavery.co.uk and the password you put on your account (when you created it)
You will then be taken into the control pannel. Click on the packages available (of which I guess there is only one) and on the next screen you should see a linke to accounts. Your FTP account details are under there.
I've always used click here when doing stuff with 1&1 (though not your domain!!)