Otherwise, your best resource is going to be an internet search. They should also have a mechanism to provide you with a replacement or give you contact information to their tax processor who produced the form for a replacement. First, call back and try again because technically these numbers for businesses are public information, so there isn't a legal reason they can't give you the Federal Tax ID number over the phone (it might be a company policy, but maybe you can get a supervisor who is willing to make an exception).