Unauthorized dr bal fee and change of account

This is probably the worst bank ever !!! Firstly I had a student account they said if I dont give proof of studying they going to move me to a gold graduate account so last year I gave them proof yet they still just changed my account! On top of that I wake up to see charges for R100 for some unauthorized dr bal fee I dont have a negative balance or overdraft why are they charging me extra !! I have to pay extra for an account I didn't choose as well as for this R100 extra ! And no one even answers or returns emails or anything ! Worst bank ever !!!