Paytm Mobile Solutions — cashback is not credited

Dear sir/madam
I had used promocode fly at flight ticketing. And an sms is returned as below;
Dear meghabarna,

Your flight booking is confirmed and ticket has been emailed.

Sxr to lko (Pnr: kdt6kg)

Mr. Okram suresh singh

Sxr to del, indigo 6e-694
Dep: 15:05 (Sat, 9 dec)
Arr: 16:45 (Sat, 9 dec)

Del to lko, indigo 6e-528
Dep: 21:50 (Sat, 9 dec)
Arr: 22:55 (Sat, 9 dec)

Booking id : [protected]

Cashback of rs.211 will be credited to your paytm wallet within 24 hrs.
Your flight ticket and travel insurance policy document have been emailed to [protected]@gmail.com.

For any assistance, contact paytm flights helpline at [protected] or https://paytm.com/care. use promo uberpaytm5 to get inr 50 off on your next 2 airport rides. T&c apply.

But till now cash back is not credited in my paytm account. May i know the matter about it???