Axis Bank — Credit card

I have two Axis bank credit cards, Without even informing me or giving any intimation, they have merged the limits on both the cards. The customer care is saying that I cannot use my new card as it shares the limit from the old credit card. I am continuously paying the amount in the old Credit card but still why limits of both the cards were merged. It is pure cheating with the consumer. What is the point of giving a new card, if it cannot be used, until you pay the full amount of last card.