Numismatic Guarantee Company review: Coin grading

I joined the collector club offered by this company and paid for membership. This was supposed to allow me to submit coins for certification. I was charged for certify coins for a charge of 40 dollars a coin. I submitted coins in October. The company indicates that the coins were received, and the first group shows that the service was done. I was charged for the service. The company will not return the coins. I have made several attempts to contact them to determine what is going on, but get no response at all. The company states that coins submitted have a turn around time of approximately 13 days from receiving the submission. They have had possession of the coins since October 20, and will not return the items. As I write this, they have over 41,000.00 in approximate value of my coins and will not return them or give an explanation for why the coins are being retained. I paid for the membership and the fees for certification. I understand that they don't have to certify my coins, but they should at least return them to me. All attempts to contact them have had no response.