MakeMyTrip India — Gift Card for MMT Holiday

I purchased 3 Gift cards from HDFC instant vouchers for MMT Holiday to be used on the Final purchase, when I made the Final payment It did not allow me to use the Gift card as the discount code was applied . The Prime usage of Gift card is to use it on Final amount even if there is a discount applied.
While purchasing the gift card I checked on main page and it mentioned Max 3 gift cards can be used . The terms and conditions were listed where we check the box that I accept the terms and conditions .
Also, as per law the Gift cards should have minimum validity of 5 years but they offer only 1 year.
They should be listed on the main page when the consumer is purchasing . I
ask MMT to cancel my Gift card and refund me the amount.