HDFC Bank — Continue negative balance deduct

I have salary account in hdfc bank from my first company after coming out of company i never used that account and i am went out of state for working. I called customer care to close account. But they told need to come to own branch. I received every time message as your account balance is zero and now also came like that. Now i am went to branch for asking closing of account they told you have negative balance for not maintaining minimum balance we kept negative balance. I shown my messages they given zero balance. They are told that is our business policy . I went another time for showing and closing that account but they told why we need to follow those rules. And we didn't received any instructions like that from our bank so you need to clear negative balance to close it.
This type of cheating customers and rbi done by hdf bank please take action against these type of cheating banks