The hackers may have the email address, but they presumably can't read the email sent to that address. Hence "email exchange".
Another option would be to send out a new password via mail to the billing address if they had no other way to do it electronically. Out of luck if you moved since then. Make the old password a requirement so mail thieves cannot steal your account.
I was pissed that I needed to change my credit card number because of these clowns. If someone wants to make a cool startup make a credit card number that is a one off that will only work for a certain time frame(extendable), dollar limit, and business name(though this one might be tougher because the business name given to the credit card company might be different than the business name I would enter).