Kotak Mahindra Bank — Not closed my account and showing negative balance

Address:

Ghaziabad, Uttar Pradesh

My CRN is 65111162.
I submit my application to close my account with Kotak Bank in Aditya city center, indirapuram branch on 16-April 2016 and their executive assure me that it will be closed in next 8-10 days maximum. and same day i sent a mail also on service.[protected]@kotak.com that i submitted my application to close it. please confirm once this account will be closed. they given me reference no. 1-[protected]. and after that i am following them continuously regarding this but there is no response and today on 6 - May -2016 when i login to net banking to check whether it is working or not, i found its showing negative balance of -1374 Rs/-.
on 16th April i left it with 0 balance and there was no negative balance. and bank executive taken my application to close it.
So, i need clarification that why this account is not closed yet and why showing now negative balance.

Pathetic experience with Kotak Mahindra Bank.
Request you to close this account.