Axis Bank — Credit card limit merge

I have been using axis Bank credit card for more than 6 years...

First I got my vistara credit card 8276...then couple of years back there was pre approved offer showing for 2 nd card... I contacted credit card team regarding how will be the limit and they said limit might or might not be merged and they informed me to use the card once I receive to know exact limit status...

Then I got the Flipkart card ending with 8684... I was able to use this card limit without any issues... So I had 2 credit card with 2 different limit...

Then after some time u called me that I have another approved card and again u said not sure about limit...then I got the 3 Rd card 5120 and I have been able to use that card limit also ..

SO I HAVE BEEN USING 3 CREDITS WITH SEPARATE 3 LIMITS...

I have been paying card dues without delay and paid all amoun nd using it again

But all of a sudden when I check now limit shows -2, 30, 437 in all 3 cards.

How will I repay now...what type of banking service r they providing...they r giving me card and allowing me to use and after using they r merging the limit...

Any one please help me with this