Yes Bank — regarding negative balance in saving account

I am having salary account in yes bank. I opened this account while working in a private firm in september 2015.in dec 2015 i left the job & stopped using this account.in last 2 half years i didn't use it considering it to be closed. But now i am getting messages of negative balance in that account. Since, it is a deposit account & not a loan account & i am not a loan defaulter, then these negative penal charges are nothing but unjustifiable advantage taken by bank for my unintended inattention. When a person is not using account for two years then why has bank not closed the account & on that adding burdensome charges are completely indigestible.
I do not wish to pay this amount when there is no mistake from my side. I want yes bank to close my account at the earliest.
Thanking you
Jaishanker