Attempting to cancel debit order

Good day, I am trying to trace a debit order mandate linked to a debt review agreement that I cancelled. I have sent numerous emails requesting the insurance part of the agreement be cancelled. It's an amount of R130 that keeps being debited for insurance and I am unable to cancel it with the bank. How do I cancel it? Nupay is the reference I am receiving on my statement. I don't know who to contact and nobody can give me any answers on how to stop this money going off my account????? I am paying for a service I am not receiving as the debt review is definitely cancelled yet this amount is not.