Credit Card payment issue:

I was using HDFC credit and Card credit limit was 2,50, 000 Rupees. I had very less usage of credit card. I had cleared the entire due amount on 31/05/12 of Rs. 1,500 and stop using that card. when called in HDFC customer care to confirm the status on C.Card, I was told that I have zero balance on my credit card. I also send email at [email protected] to update my current mobile# in their records and cancel C.Card. Presently this is blocked due to no renewal.
After one year near to September or October 2013 these people called at my home town on my father’s mobile no. to tell that I have 6000 Rs. Balance due on credit card. I again called with concerned person they told me that there is 89 Rs. Fin charge on my unused credit card and after may 2012 to till today there is due balance of Rs. 6600. I asked for credit card statement. Their executive told me that due to block of my cark they can not send my credit card statement at my email address or at my correspondence address. The executive told me that if I will visit their branch in Narayana they will provide my credit card statement. I went to their hdfc office in Narayana. I did not find the same person there with whom I talked on call. The manager Sumaya and another employee denied me completely to provide the C.Card statement. And they were not able to explain me the complete detail of my statement even though they had my all emails which I forwarded them to get them remind that I have made entire due amount on May 2012.
They were keepon telling me that I have to pay Rs. 6600. Without providing me any statement.
How come it possible to pay Rs. 6600 for fin charge of Rs. 89.00 for which, I was never informed and I never did any shopping of single penny after May 2012 on that credit card when I made the full payment.