MakeMyTrip India — refund promised but never made

I had rescheduled my flight dated 29th september-02nd october to 30thdec-14th january. The website confirmed the booking to me, as shown in the attachment, and had promised me a refund of rs: 7368/- but i never got the refund amount, and when i called them for inquiry, they said that in their records, there were no such transaction made. Now today already it is 29th, they havent responded. Also, yesterday i called the customer care and spoke to them for 3 hours trying to convince them. Why should i convince them to return back my money??? I had paid total rs: 21 thousand for the entire flight and they arent refunding back any money. This is intolerable.