Unauthorized Debit

Unauthorized debit order ,double debits were made on my account by Nedbank for the past 5 months. I had an payment arrangement with Nedbank loans however that arrangement was not honored an amount of R5000.00 was debited in December without my consent and last week a R1000 .00 went off from my account excluding my actual debit for the loan . Mt name is Bathini Gugwini ***