let me tell you a little thing about credit cards. any problems with merchant, you get your money back. they charge, more than what you authorized, you get your money back, they do unauthorized transactions, you get your money back. all it takes is a phone call.
on the other hand, if you pay with a debit card, chances are, your money is gone. unless there some kind of unauthorized charges.
so always pay with a credit card online on merchants. never, ever pay with adebit card.
that thing they credit card companies tell you about not being liable for unauthorized charges, it's because that is the law. any problems with the quality of whatever you bought, you dont have to pay it, as long as you return it, that is also by law. so you would have been pretty much covered if you had used a credit card, since it looks like they misrepresented. but with a debit card, who knows.