Cash stolen in bank premises.

The security guard is employed by the bank for its own safety and security and not to provide security to the customers against such thefts.

Hence Bank cannot be held liable for this act.

You can lodge a criminal complaint against the thiefs with the local police.

But in a similar case in 2016 NCDRC held that if such incidents happen inside the bank premises, the bank is liable to compensate because it is banks duty to give security to their customers inside the bank.

As experienced every Bank branch has deplyed armed security guard, it is not understood as to how your branch did not employ, if your statement is taken as a true story.

How can guard(s) provide personal security to each and every visitor / customer of the Bank, is it possible ?

If youstill  feel that it is bank's responsibility to provide security to its customers inside the bank premises, you can proceed with your proposed consumer complaint for deficiency in service against bank.

Before that please confirm the law about it and then proceed 

The subsequent post by one mcw19 conveys no meaning besides it is totally an irrelevant topic to the subject of this thread 

agreed with above ciews.  You seem to be already aware of the precedence.