FNB allowing unauthorized debit orders that they don't want to reverse

let start here im gonna be changing banks soon, its been way overdue

i was double debit yesterday and i never gave authorization for that and this the first time but these are different people now deeping into my account and i am unable to reserve that R1509 and all FNB wants is for its customers to go into debt with that idiotic relief solution they have, what do i need them for if people can go into my account and do as they please ? i need this to be reversed ASAP