HDFC Bank — Charging Financial charges

Address:

Pune, Maharashtra

My better half, took HDFC policy in 2008
For that agent came to office and giving the info about the product, as per his info, the premium has paid from my credit card 20000 yearly, for this transaction there are not other charges applicable except processing fee @ 200,as per this info HDC executive statement I bind the policy.
in 2008 i am not facing any issue regarding the payment, but in end of 2009 HDFC charged me finical change around 600 every month without any information.
i had tried to reach HDFC CC and visited so many branches for resolving the issue, they are not processing 20000 amount in EMI in complete year 2010 and charged me finical change against the amount 20000.
Number of time I had asked to HDFC CC why you are charging this amount to me, but they are not ready to except their fault as they are not convert total amount in EMI at year 2010.
Now at till date HDFC charged around 5000/- extra amount as financial charge.
Please let me know what I should do for same.
Thanks
Sneha Nandurkar