I think this where I'd dispute both credit card charges (the original one and the new one that appears to just be a shipping charge) and let them sort it out. Maybe wait to see how this plays out since he'd be 100% in the right to revoke your credit as soon as he gets notified about the dispute (since if you win the dispute and keep the credit you'd come out with an extra [amount of the credit] in your pocket).
Other than that, consider the money gone and bridges already burned. On the assumption that you won't order again, disputing the charge is of virtually no risk to you.
Fun Fact: Whether the merchant wins or loses the dispute, they pay a non-refundable charge every time it happens. I had a lady spend $200+ at my store, got a *single* rotten orange, which we offered to replace for her. She disputed the charge, we won, but still got dinged $15 by the processor. I've had times when I KNOW the business is 100% in the wrong but I also know that I'm very unlikely to get my money back via a dispute, but went ahead with it anyways just as an FU to them for being a generally crappy business to deal with (car dealership).