There was some problem in the Smartbuy payment system... issue has been resolved now... your transactions should get reversed... I also had the same issue with a hotel booking... infinia concierge confirmed that the transaction will get reversed in 5 to 7 working days and I made a new booking today which went through...
If you have doubts contact hdfc credit card helpline.
Check your orders/bookings in the smartbuy page to see whether your booking is reflecting in Smartbuy or not. If it's not showing then most probably the transaction will get reversed.