HDFC Bank — iphone 11 cashback not received

Address: HSR layout, Bangalore

I have purchased i phone 11 on 01-Jan-2020 from Venkateshwara Enterprises, HSR layout, Bangalore was entitled for 6000 cashback for debit card transaction within 120 days, its been more than 4 months and i have not received cashback so i am here for the complaint i also have the bills and receipts for the same hoping for resolution