Close gold check account

so FNB charged me R100 for a debit order that bounced for R37.83, i dont understand in which planet does that even make any sense , i was charged a total of R300 for unpaid debit orders , one for an amount of R200 , R530 and the other one is R37.83, i really cannot live in fear that ill be charged this much if my debit order bounces ,

i want my Check account closed , i'm better off without it