Kotak Securities - Hidden charges for a zero balance account

I opened a zero balance account, I got a kotaksecurities account with it. At beginning CC people call me and book stock and close. As usual I have lost *k, after that I requested to close the account. There is no further information. They spacing my inbox with interest and charges. I have paid that also. After made that payment they came again and say. You have to pay AMC charge now. And also they are not going to close my account and create charges and get money from me. That's what their usual intention. While creating an account they came to your door steps but for closure they will ask n number of forms and restriction you not close and charge you for this and that's...