Hmm - Well, that's correct. Is it confirming you have a support account under that e-mail, and are you certain that that is the registered e-mail on your account?
If so, you may want to try creating a new support account and adding your original e-mail to the new account - It's possible to tie several e-mails to one support account, as long as you have access to them. I'm not sure if support can reset support account passwords or not, but creating a new account and tying in the old e-mail would work for contacting them and getting help, even if they can't reset the old support account's password.