Which credit card gives the highest cashback on online shopping?

On credit limit increase: most banks auto-review every 6 months. If you use 30-70% of the limit and pay in full, you'll get an automatic increase. Don't call and ask for it explicitly — banks take it as a sign of credit hunger and sometimes lower the limit instead.

I closed my HDFC card last year. The process took exactly 7 days. They sent a confirmation email and a closure letter by speed post. Tip: pay off the full outstanding and request closure only AFTER the payment reflects. Calling repeatedly with a zero balance is the fastest path.