In utter disgust

Do not know what to say anymore, I have been trying now nearly a year to change my debt protection plan's beneficiary from one person to another without success. Email after email and still no results. All I get is "change/maintain via the FNB APP" however this does not happen as the app keeps on giving me an error that I cannot do so "Please contact the Bank". How difficult is it for the staff just to READ the email properly and change the beneficiary from my older sister who died to my younger sister????