HDFC Bank — Purchased IPhone Through HDFC Credit Card did not received the cash back

Address: 532 Rafi Nagar opposite Mohan Singh Eye Hospital Raebareli Uttar Pradesh 229001

I have purchased iPhone XR 64 GB through HDFC Credit Card. I have been charged full amount at the time of payment through credit card.Although, I selected 6 months emi which included 0% Interest. But at the time of billing it showed Rs.2200 interest was charged and was been told that this will be get refunded with the cash back as Rs.5000 was the offer for cash back. So total Rs.7200 was promised to be credited as a cash back after the purchase.

Date of purchase - 09/03/2020
Purchase From - Unicorn Infosolutions Pvt. Ltd.
Address - Shop No 6, GF, One Awadh Center Mall, Vibhuti Khand, Gomti Nagar, Lucknow-226010