Ridiculous security checks

I logged a complaint to Standard Bank’s email platform and received a mail with a reference number. Then received a call from the Centre requesting my full ID number, contact details and physical address as verification. Unfortunately due to security reasons which I am sure a bank can appreciate, I am only prepared to provide a part of my ID number with the rest of my details which they refused and not willing to help me further. How is that possible??? Rather send me a OTP which I can provide and identify myself with. Surely there is another financial institution that’s more up to date with security features?