State Bank of India — SBI Claims outstanding which I disagree

SBI have issued a credit card to me , as per Call Centre this card was given to me free of cost but they have started asking for an amount as fees. I treied to resolve which agin they said resolved but bill were raised again. An amount of Rs. 416.75 , was to be paid by 1st Sep which I have not now today I got an SMS stating pay Rs. 862.22 by 11th Sep. What is basis of these calculation, even if it is late fees aginast no outstanding finsed should be caluculated and due date should be 1st Oct. Do I conclude SBI will do what ever they want. I want to see if I will not pay what they are going to do with me.They keep calling me and harrsing me to pay. Every day I get four calls. If they continue calling me I am going to cut Credit Card into four pices and send tham back.