HDFC Bank — cashback not received

Address:

Meerut, Uttar Pradesh, 250401

Sir i purchased mobile from flipkart on 26 Aug 2019 My order Id is OD[protected] my account no is [protected]
Where they have mention to give 5% cashback after 3 month now its more than 3 month and i still did not get cashback in cashback redemtion option in debit card section in net banking service
Kindly give my cash back of rs 500 as i purchased for rs 15000 (max 500 cashback)