Yatra.com - Refund not given

I booked my ticket to Boston and the flight got rescheduled just * hours before the departure. I had to cancel the booking the same day on **th March **** and the refund request was made. So many phone calls and emails have been exchanged and I was assured that the money will be refunded within * weeks. It has been more than * weeks now that no response from the company. In fact, they have stopped replying to my emails and hardly have an answer when I call their customer care. In fact, they issued the ticket without the ticket number and it had an only a yatra booking number. So I can't even call Delta airlines for the refund status. They are a big cheater and must be booked for their frauds.