I hold salary account with ICICI, that's why they are generous. You might be holding your salary account with hdfc I assume.
My hdfc credit limit increase was 3k, from 1.36 to 1.39, felt like a slap on the face, so I dropped few mails to grievance, and after not getting any response, closed the card. Still the pre approved option shows me paid Millennia, while I just closed LTF Millennia from them 🤣, very weird bank algo.