Trying postmaster is a good idea, but I see the main problem differntly from you: as far as I make out, what I am trying to do in situations like this is to get _past_ the customer support person (who might be working from a script, and might be working without any authorisation at all) and to get the situation escalated to the managerial level where someone *can* take an action.

If the information isn't publicly available, 'who do we need to contact to resolve this' is a legitimate question. (And yes, I've dealt with this on both sides of the equation.)