any suggestions on how to fix this?
Yes. There's solution!
Finally I have manged to buy using my HDFC bank debit card.
See
confirmationfrom MS
Are pre-paid debit cards accepted?
Yes, pre-paid debit cards are accepted from supported payment types such as Visa or MasterCard. The cards must also be ecommerce enabled for online purchases, capable of cross-currency transactions or purchasing in foreign currency and do not require a pin to complete transactions. Only one form of payment can be used to complete the purchase. Ensure that your card covers the price of the download, the optional upgrade DVD, shipping and handling and applicable taxes. Some cards may also be subject to pre-paid card fees which vary by provider. We recommend that you acquire the card in the country in which you intend to purchase
Windows 8 and that you retain the card after your purchase. In case of return or refund, the amount of the refund will be added back to the card used to purchase Windows 8.
You can use your debit card. But the card should not ask for a password or pin on payment. So you should try a virtual debit card which will not ask for a pin on payment.
I have done this using
HDFC NetSafe card. I created a virtual card from HDFC Netsafe and used it for payment. Bingo! Got my product key in next screen.
You can try similar services like entropay.com for this, if you are not using a hdfc card.