Hi,
Please check with INSEAD's admission officials for payment through credit card option. If you were not able to find the option than probably it must not be there.
BTW why do you want to pay through your credit card? How are you financing your MBA?
I would not recommend credit card, even though your card has high enough limit because you would need to pay the CC company according to your bill cycle, the interest rate on credit cards are generally high in case of default.
Thanks,
Harish