Financial giants acting immorally

Standard Bank handed me to the lawyers for unpaid credit card which i then settled in October 2016. To my horror standard bank handed me over to a different lawfam this year for the same credit card i settled and received a settlement letter for. As if that was not enough, upon enquiring i was told that standard bank insurance division, continues to levy their so called monthly fees on a redundant card. That card seized to exist the moment it was handed over, one couldn't utilize it for anything. It has been over three weeks since i spoke to standard bank credit card, insurance divisions as well as physically going into their branch, and nothing has been done about it, not even a single call of acknowledgement. in the mean time, i have been adversely listed on the credit bureau. What can one man do against a huge financial giant acting with pure impunity? I am at my wits end and i just have to wait for two more weeks to pass for the ombuds to hear my case. Wow astonishing