Kotak Mahindra Bank — Adding late payment fees again and again and asking to pay when i paid with in the time line

Address: 500032

This complain is regarding credit card bill issue. First they added a late payment fee of 500 where i paid within the given time frame. I mailed them and they told the late payment was waive. Again in the next month the late payment was added with the late payment of current month. I already paid all the bills with given time frame. I have the transaction number and snapshots also. They are saying me to pay again those late payment fees. Also they are neither replying to mail properly or attending any calls. Money used to deduct from mobile but they never used to respond. Its pathetic/ they are simple cheating. At least grow up guys. Such service is shameful. It is the first time i came across with such pathetic credit card service.