Standard Bank blatantly ignores their internal customers.

I am so frustrated and annoyed with the lack of ability to do something that I feel should be relatively simple. I've recently immigrated from South Africa to the Netherlands, and occasionally I will still want to do transactions from my Standard Bank South African bank account. The problem is that all of the OTP and 2FA verifications go to my old South African number which I no longer use. I have sent multiple emails that have been ignored, as well as have been on 2 different 1 hour+ international calls with the standard bank call centres to either switch the number to my new Dutch number, or to switch all 2FA verifications to an email OTP. Every time I am told at the end of the call that it has been done, but every time the OTP/verification goes to my old number and I can't do the transactions without switching to my old SIM card. If this is the kind of service that Standard Bank displays for international clients, I'm moments away from moving all of my Rand to a different South African bank that can actually help me when I have queries, and not just blatantly ignore my emails.