How to dispute a wrong transaction on my credit card

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.

Yes the rewards sound amazing in marketing, but the redemption catalogue is full of products at inflated MRP. The statement credit redemption is almost always the best value. Skip the merchandise, skip the flight bookings, take the cash.