Nedbank Poor Service

Nedbank debited my bank account on the 13th of December 2019 for the personal loan that I have with them. However, I was not informed that my account will be debited on that day. So I have reversed the debit order. Today I called to find out what happened and to get clarity on when my account will be debited, however, the consultant who was trying to assist me could not authenticate me, because her system still reflects an old cellphone number which I use to use more than 10 years ago when I had a savings account, which I closed more than 10 years ago. I told her that on my loan application I completed my current cellphone number, I dont why their system is picking up the old number. She told me that I need to go to a branch to have that corrected. Unfortunately, I am not going to go a branch to fix a Nedbank administrative error. Could you please get someone to contact urgently regarding this matter.