My brother’s POSB Account got compromised

He is just a poly kid who worked hard to save his moolah. One day, he fell sick and had to visit the clinic, only for his card to be declined. He found that most of his savings were wiped off due to an overseas transaction. He did not enter any of his bank account details or OTPs anywhere…

1) reported to the police, police pushed the blame to the bank. Police claimed that nothing can be done because its an overseas transaction.

2) called the bank, bank said police have to do an investigation before they can do a refund.

3) went back to the police again and they said they rlly cant do anything.

Anyone experienced this before? If yes, what can I do to help my brother get his money back?