Dear Sir,

I am a customer of HDFC bank .
Problem: I have gold master card.. I had purchased worth rs 900/- in the mar 26th 2009. The interest rate is 3.25 - 3.5% on the card. Late fee charges is Rs 350.
I have paid dues in the month of october(around 15 th).. (almost after 6 months)

so, @ 3.5 % interest = 900 + 31.5 + 32.6 + 34 + 36 + 38 = 1074.
late fee charge = 1074 + 350 = 1430

BUT,THEY HAVE CHARGED ME RS. 3700.
They have charged around 400% in 6 months?? How can they charge so much?? Do they charge late fee of Rs 350 every month?? how much will they charge for service??