HDFC Bank — iphone cashback not received

Its been already 4months since i purchased iphone and still didn’t receive my cashback that was promised by hdfc. I spoke to icare and was informed that i’ve to check this with respective bank. I tried calling the customer care to which i got no proper response. Is this how a big company works? Disgusting! 6000rs might be a small amount for a big company like yours but not for us. Are you doing this on purpose hdfc? Am i being fooled?