IPhone & banking app hacked!

My son was held up by 5 men with knives and his cell phone ******. His phone and banking app had facial recognition and security codes on them, but despite this, the phone was hacked as was the banking app, and a lot of money taken out of his account. FNB has said that the passwords were compromised. My question is HOW??? That means that 2 passwords were compromised... The ***** investigator says that the passwords were saved somewhere or my son gave them out or he accessed them and the ******* saw them and took note. I say NONSENSE! Apple support says that an Iphone cannot be accessed without the code or your face for facial recognition (as it is 3D) but it was! The banking app was also accessed! Some money was recovered but there is still money that was lost due to no fault of my sons. The bank is very unsympathetic and says that you accept T&Cs when you download their app. My last word is... the banks are encouraging us to use their apps on our phones. They are warning us endlessly about phishing emails, ATM ***** and not giving out your OTP, but they are not warning us nearly enough that if your cell phone gets ******, it can be hacked as can your banking app and money can be ******. When you challenge them, they throw their hands up and say sorry, you accepted the T&Cs??? What are they doing to prevent this happening to other clients? What are they doing to make their apps more secure? Why aren't they warning us a lot more that this can happen?

I will be taking this further as I am very unhappy as to how this was handled.