[Resolved]  HDFC Bank — Regrading converting salary account to saving account

Address: Bangalore, Karnataka, 560010

My salary account (In hdfc bank) was created in my first company, so once i left the company and joined somewhere else i had to open another salary account.
Now my salary account in hdfc bank has been converted to savings account (Without informing me or warning me).
After leaving the old company i never logged in to my account through net banking. Now it's showing me negative balance in the account.
Where should i approach to close this without paying any amount now. Please help.