OTP without e-mail option

I'm overseas, trying for more than 2 weeks to have my OTP changed to e-mail or another phone number, since my phone from South Africa does not work in my home country. Nedbank call centre informs me this is not possible and I must have roaming on to allow for the 'accept' thing to work, and the local branch keep changing e-mails with me, but don't give me any option.

My husband, who also travel abroad constantly, has an account in another bank in South Africa, and they easily allow him to change the OTP to email when it's necessary, so why Nedbank cannot do the same? Specially when they know that I'm a foreigner client. I 'm really disappointed with this.