Product: Checking or savings account

{$25000.00} was stolen from my savings in an account I have with Chase Bank. The XXXX unauthorized withdrawals occurred between XX/XX/XXXX XX/XX/XXXX and all contain the same legend describing that the withdrawal is to pay for a Chase credit Card ending in XXXX. I notified Chase when I first saw the unauthorized withdrawals on XX/XX/XXXX. The Chase representative I spoke with on a recorded line said I would get my money back because the unauthorized withdrawals were all going to pay a chase credit card ( not associated with my account ) and Chase could track and retrieve those funds. A few days later on XX/XX/XXXX, I went to the Chase branch near my house to check on this. I was told that Chase would only restore some funds those that were beyond 60 days from the date of the first unauthorized withdrawal would not be restored. They cited a 60 day rule that allows Chase to not restore those funds to my account. Of the {$25000.00} stolen, Chase returned {$11000.00} ( XXXX of the XXXX unauthorized withdrawals ) to my account. I asked Chase to escalate my claim for the remaining funds {$13000.00} however, on XX/XX/XXXX, the escalation department also claimed that that the 60 day rule prevented chase from returning my funds. 
I attempted to explain to the Chase representative, these funds belong to my XXXX mother, who has banked with Chase for over 50 years. Since XX/XX/XXXX, my sister and I have been helping my mother to handle her finances as her cognitive abilities began to fail. In XXXX of XXXX, we moved my mother out of her apartment and my sister, and I have been handling her care and her finances completely as her XXXX is worsening. We have jointly paid her bills from her Chase checking account exclusively. The XXXX account was never used to pay credit cards or any other bills. 
I, like most Americans, entrust my funds to a bank believing they are safe. I am unfamiliar with a 60 day rule. Moreover, the Chase representative admitted that Chase can identify the chase cardholder that withdrew the funds and Chase will recover all of the funds that were unlawfully withdrawn from my mothers savings account. The bottom line is that Chase will be enriched by {$13000.00} and deny the rightful owner, my mother access to her money saved for her health and aging. 
This is an outright theft. Had these funds been stolen from my mattress, the statute of limitations on theft in all states is longer than 1 year. I find it incredulous that a bank, who touts that deposits are safe with them, has a 60 day statute of limitations. 
At the very least this is unfair deceptive and abusive to the depositor. Chase advertises that they are always working to make banking safe. They also advertise " If we spot suspicious activity on your account, we may place a temporary hold on it. This is an extra security step to help ensure it's really you and not someone else using your account. '' Why didnt Chase spot this suspicious activity, large and frequent payments made from a savings account not used to pay bills, to a Chase credit card not associated with the savings account. 
My sister and I are sick over this unfair treatment. We need these funds for my mothers care. Please help us to recover these funds.