Nedbank debit order reversal not an option for clients

Nedbank advertise that they offer a facility on their MoneyApp which allows the client to reverse a debit order. This information is NOT correct as Telkom have repeatedly been presenting an unauthorised to Nedbank which is being deducted from my account. When I queried this a Nedbank consultant advised "Debit orders that would have been authorised prior to you cancelling will not allow you to reverse. This would be due to a active debicheck mandate. Please note that you will need to contact Telkom to cancel the debit order." The fact that I have repeatedly informed Nedbank that this debit order has not been authorised and that the Telkom contract was cancelled in October holds no water with the bank. Their answer "report the matter to SAPS" while continuing to pay out funds from my account!