Disappointed and Disgusted

I've been a very loyal client and happy with the service you've given me until today when I went to one of your branches and was attended by Theresa at Jabulani Mall Soweto FNB branch . I wanted to reverse a debit order . To cut the long story short , she told me I was charged bank charges . Bank charges that are new to me and were never explained to me . Yes my account had insufficient funds and an unauthorized debit order went through on my account but why am I charged R100 bank charges for that . She just told me she can't help me and I must just deal with it . I am really disappointed with your service and money out of my account without my knowledge . I will be cancelling my account as soon as I'm done paying my loan .