HDFC Bank — saving account - security concern rs 10000 transferred to hdfc sec without my acceptance

Address:	Chennai, Tamil Nadu, 603202
Website:	HDFC Bank

Today Rs 10000 was reduced in my account suddenly, When I Called the customer care representative, She given me HDFC Securities (shares) Contact number asking me to call them to know what happen to my 10000 Rs. I was shocked to hear that being a customer for 12 Years.

I deposited my Money HDFC Bank, means they are responsible for my money until unless I make any mess with the transaction.

Later come to know that 10000 Rs was taken by HDFC Securities instead of 2000 Rs. Without my Authentication.

I am still not understanding if it done by any other securities company, Will I get the same answer.

Who given authrization to HDFC SEC to hold 10000 Rs ?
You HDFC Bank & HDFC SEC are one company so trying to cheat the customer?

Bad news is the customer care Reps on both side are Sooo Careless.

I understand one thing here, Do not keep all engagement with one bank.