Citibank — Abruptly changing my banking account type, NRV, within months after creating the account

Address:

Bangalore, Karnataka

I had opened an account with City Bank, about 10 months ago. They changed my account type to "Suvidha account" after just 3 months and raised my minimum balance, abruptly without notice they deduct Rs. 250/- each month, if I don't maintain that that balance and they were deducting it, without even informing me. On calling them, they are saying that I've changed the company that I work for and that's the reason.
And now they are Changing it into some other account type, requiring much much higher NRV, and are deducting Rs. 500/-, if it's not met. All this, without any notice.