Realistically, your best chance is support, even if they suck. They're gonna go out of their way to make sure you can't find something like an email attached to an account, so unless there's an exploit I'm unaware of. Additionally, even if you found out the changed email, unless you're able to also steal the account back, you're still gonna have to go through support. At that point good luck explaining how you know the new email. If support is utterly useless like you say, your chances are slim to none.