It is crazy how people panic when they receive phone calls like these, the scammer is either telling them something is wrong with their account, or that they are in one trouble or the other. I cannot imagine falling for something like this, so i get shocked when i bear that there are actually people losing a lot of money this way, they withdraw their money, follow the scammers instructions, go to a BTM, buy crypto and send their funds to the scammer, through the QR code their provide *facepalm*.

I don't think there is anything the bank can do, as long as you are not withdrawing above a certain threshold, and do you expect mobile network operators to spy on people's calls? Not going to happen, so you cannot blame them. Neither should BTM operators be targeted for this, it has always been easy for the authorities to blame BTC and BTC services.