Asking DEAF senior citizen for security questions over phone how stupid are you?

Nedbank why do you discriminate against deaf people? My mother of 70 years installed money app and the only way she can use it is by answering stupid questions over the phone via voice call. She cant hear. I want with her to the bank to add new phone number in order to use your stupid app, but your stupid consultants wont tell us that she would need to answer stupid questions over the phone, why? Secondly why is it so eazy to open a thyme bank account without speaking to people?