SBI Bank — Transaction error which caused loss of 1.5 lakh from the accoint

Hi,
I am a software proffessional in Hyderabad. My sister is a hopusewife and she has saving account in SBI bank. Recently when she tried to withdraw money from her SBI account, she was unable to withdraw any amount and she notices 1.5 lak is missing from her account. She ran to SBI branch and tried to figure our when she has not withdrwn any money and she only has the debit card how could this happen?
But SBI bank declined any assistance to her. All the transaction happened in Chennai whereas she lives in Kokkata and never been to chennai ever. But still SBI bank is not helping her to get her money and harrasing her in every respect. She is not very aware of all the various transaction type. So she was misled by SBI by stating that it seems when SBI checked the transaction they found the paasword in the system and they told to my sister the debit card password is her so bank is liable for this. Now how it is possible for anyone to see the password that one has eneterd while taking the money. Ity is a sensetive infoprmation which is not even being disclosed to bank people so how could one can see the password logged in the system. They are cheating big time. I am writing on her behalf as she is not aware of all this system. So please let me know what best we can do to help her.