HDFC Bank — negative charges charging for every month

My wife have salary account opened by company... After 1 year she quiet the company... Immediately hdfc bank converted her salary account into personal without any intimation and now they started charging for not maintaing the minimum balance... Actually last 2 years we both are in out of station when we came back to india and check the account balance is shows in negative amount... Called the hdfc customer care to close the account but they asked us to visit respective branch... It's very worst service... We are not ready to pay the amount charged by bank since if the account is idle for many years they have to close it instead of charging... As per the rbi rule, no were mentioned for personal account to goes till negative amount... So please close my wife account...