Big Bazaar / Futurebazaar / Future Retail / Hometown — Cash Back not credited against Order no.[protected]

I am Satyajit Karmakar ordered few items in Big Bazaar Online( Store-J.C.Tower, Ranchi). As per my order an Cash Back of Rs.51 needs to be credited in my future pay wallet after delivery of my order. The offer was buy Patato @Re.1 per kg and the T&C was "You need to pay listed price @Rs.18 per kg and post delivery the differential amount should be credited back in future pay wallet. The delivery was happened on 14.05.2021 and now 3 days already past but the cash back still not credited in my future pay wallet.
My order no was[protected], dated-12.05.2021.

Please do the needful.

Regards,

Satyajit Karmakar
Mob. [protected]