You can also avoid the call center by looking up your favorite source of executive information, finding the name and address of someone like a VP of Customer Relations or what have you, and writing them a polite, businesslike letter on dead tree explaining what happened and what they need to do to make it right for you. This will get read by their secretary, who will call the switchboard, ask to be transferred to the person in charge, and say "The Boss wants this handled now." And that is about all it takes. (Well, apparently the VP in this case was not great, either, but you could have shaved two months off the resolution time by contacting her earlier.)

I've had to do this to a bank or two which was under the mistaken impression that I owed them money. Incidentally: a tact I particularly like, since I own shares of essentially any publicly traded stock by dint of owning broad index funds, is to send the letter to Investor Relations. Just say you're a shareholder (you are certainly not the most convoluted situation that results in getting invited to their shareholder meeting) and that you've had a problem, blah blah blah, please fix at your earliest convenience.