Go on the attack. There was no way for you to know this. Let them know that you will be reporting them to The Consumerist, Better Business Bureau and that web site linked earlier. Clearly identify to them that the PR hit they take from this will make a few hundred dollars in credit look like nothing. See if that changes the icy nature of their response.
Thats not going to work via this channel, facebook is the way to go and the BB forums. These idiots clearly have nothing to do with BB beyond "trying" to resolve issues of a client side nature.