Insufficient debit order change fee

Standard bank provided me with false information, they promised me that if I bank with them I'll get a lower interest rate on my home loan. I did switch my home loan debt order to standard bank however nothing changed. I called to cancel the arrangement of the debit order, I was told to visit the branch. Now I have been charged insufficient fee for nothing they refused to debit from my old Capitec Bank account. How do I visit the branch with my positive covid19 status.