Reversal of unauthorized debit order, 100 per bouncing debit order

I am very upset with fnb. I have an unauthorized debit order come off yesterday. I've been calling fnb since i saw this they refer me back to my app which won't allow the dispute because it is 1,000 and more. Due to this all my small debit orders including funeral covers have bounced, what will happen if my family members dies now with an unpaid policy? I wake up this morning only to find all my small debit orders of 5 or more have an unpaid amount of 100 which I now owe fnb. I am sitting on minus 638. Imagine on these taff times of covid. I am leaving this damn bank asap.i will not stay. Not considerate at all. I need the debit order reversed n then close my acc please. Im moving to capitec. Thanks but no thanks.