Airtel — cashback not received

Address:

517501

Hello,
I have recharged my airtel mobile no. Using airtel payment bank, and as the offers available i am availing 50% cashback (Max. Rs.75) of the recharged amount.

I have done a recharge of rs.509 on 15 february 2018 but until now i did not receive any cashback.

Recharge done on[protected]:56am, mrp:rs509.00, gst 18% payable by company/distributor/retailer:rs77.64,
Transid[protected].

Please provide my benefit.

Thank you
Chandu