Sachin Shah — charging interest

Address:

Ahmedabad, Gujarat

Kotak credit card charged me interest of approx rs2850 in last statement and total 5000 in last 3 months even all amount paid. I just late by 4 days but amount was more than lacs so it took 3 days more. My kotak credit card no is [protected] in name of sachibhai shah.
I called customer care and explain reasons but still they charged me very high interest and reversed only minor amount.