Two R270 debit order for same transaction

Why do I get same amount(R270) ploan debit order deducted twice every week and then fnb double the charges on that debit order it's been going on for months last wk I enquiried about it and only 1 R270 was debited now this wk we back to with double deduction that will have 2 charges myb it's another way to make money by increasing charges