Yes Bank — account closure

Address: Kolkata, West Bengal, 700001

Hi, my account no is [protected], registered on my name suparna mukherjee.
I have successfully completed the account closure process in yes bank, dalhousie branch, kolkata on dec'2015. But still i get calls and sms and also threat calls from the bank saying my account is not closed and i will have to pay all the remaining amounts charged because of insufficient balance in my account. I have explained several times that i am not a defaulter by any chance but still no action is being taken.
I want this account to be closed immediately and wave off all the charges levied against my name.
Can anyone help on this.