Nedbank are terribly unhelpful!

Nedbank are ridiculous to work with. I gave notification that I was selling my home on 9 March 2020. I received email confirmation of this. Nedbank are now refusing to waive a cancellation fee as I have been told that the employee concerned did not enter the necessary information on their system. How is that my fault? How can I be penalised with a fee for their employee's negligence? I am so unhappy with Nedbank. This is disgraceful