Cheating in cashback on mobile ticket

Location/place: pune

Name of company/service: Makw My Trip

I have booked 4 tickets with no NU79037951240904
NU79037951241740,
NU79037951242452 &
NU79037951242894 on 10th may from mobile with some cashback code. With that I should get 50 percent cashback on every transaction. But till date no single money is transfer back to my account. I have contacted there forum 10-15 times and called numerous times but they are not responding. It’s almost 2 month s after journey and still they haven’t return my 1500rs.

Thanks
Sanket