FNB Bank Costs Are A *******!!

I have been with FNB for over 20 years. Granted I misjudged my bank account this month which was my fault, so a few of my debit orders were returned unpaid. FNB has charged me R100 per returned debit order!!! 2 of the debit orders were for R100 each - that is 100% of the debit order!! Why can they not charge a percentage of the returned amount? You cannot tell me that it costs the bank R100 in admin!! "How can we help you" should be changed to "How can we rob you" I shall be changing from FNB forthwith, and not to FNB as they love to advertise with everything they can do for you that other banks don't. Apparently this includes charging an absolute fortune for bank costs to supplement the the things they can do for free for other people. A total *******!