JM Bullion wrongfully tried to charge sales tax Dallas Texas

I used the JM Bullion website to make a purchase for foreign gold coins of approximately $6000 on June 17. When I approved the purchase they added sales tax for Indiana. I checked Indiana law IC 6-2.5-5-47 and it says that coins and bullion which are IRA eligible are exempt from Indiana sales tax. The JM Bullion website said the coins are IRA eligible. I couldn't cancel the order until June 19 because it they were closed for the weekend. When I went to cancel the order they tried to charge market loss fees. Lucky for me the credit card on file had recently expired so they couldn't charge them (The order was to pay by check). I think they are trying to get some people to cancel orders as they only make money on a cancelation but never loose.