HDFC Bank — Mac book air cashback not received

I purchased a mac book air on 5 jan 2020, from my hdfc card. As per the policy i was supposed to receive a cashback of rs.6000 within 120 days. But i have not received the same.
I had also mailed to the customer services department of hdfc but have not received any response. This is really disappointing to see how the customers are treated.
I request you to initiate my cashback of rs6000 as soon as possible.