Bench Craft Company Unauthorized Credit Card Charge Internet

I was contacted by their sales rep and agreed to do a 3 year contract. He advised me that I would receive an invoice and a proof of the ad within 10 days. Today I received the invoice showing that my AMEX had been charged for the full amount of the contract (definitely not authorized, either verbally or otherwise) and that the contract was for 12 months instead of 3 years.  I called to complain and cancel the contract and was advised that (1) they have a no cancellation policy and (2) I was pathetic.