You can try to lodge the report online for your dad since the event has passed. I did it online a few weeks back when I lost my mobile phone. The case gets directed to the nearest police station, an email will be sent to you with the case number, and a police will contact you if they require further information.
With that case number, you can contact the bank and give them the details. There should also be a CCTV near the ATM for them to investigate and trace.
Here's the online link to lodge your police report. You will need singpass to login.
http://www.police.gov.sg/e-services/report