I too received the recent audit letter from World Reserve Monetary Exchange concerning an additional charge for future Certificates of Authenticity. I am filing a complaint (found online) with my local attorney general's office consumer fraud bureau and will be attaching all of your comments as well to my complaint form.
I would suggest that you do the same. Unfortunately, I bought not one but two sets of these coins and I will not be paying them any additional monies for anything whatsoever.
I would definitely be willing to join a class action lawsuit. If anyone has any information on that, please post it.