Wow, that is a pain. I wouldn't give up trying to get to someone who can permanently fix the problem. I would redo the email, and send it to network management too. Even if it is wrong, the email doesn't take any extra effort, you are already sending it to the provider relations email. I would be a little forceful in my email ... "This is my SECOND request....Even if I have the wrong email please respond with the correct contact information...." It's worth another try.