Contridicting Info Provided

I went to Capitec Bank in Bellville on 9 December 2017 to change the cell number that receives the sms on my grandmothers account. I was told I am not authorized to do it. She must come in and do it. Due to her age (86) she is no longer capable to do it. I informed them that she is not medically fit enough nor can she speak clearly anymore.

If I wanted to ***** money or close the account I probably would have understood, sort of. But I just wanted to change the contact number.

About 4 months ago: I saddled up my gran (this takes about 2 hours) to go to Capitec Bank to give me authority to do business on her account. I was told after this visit I can do any business on her behalf as of now, she no longer needs to accompany me. I was even given a supplementary card on that day.