Did not give consent to debit orders

They debited the premium twice in February and I was told they cannot reverse amounts less than R300 so I agreed that they keep the extra installment for March and they would not debit my account in March. Guess what?! they debited the installment of R120.04 plus R50 and are still telling me they cannot reverse amounts less than R300.. Who's problems is that? I want my money back. I spoke to Samkhelisiwe before 1pm today and asked that she get her supervisor to call me back, guess what ? the supervisor was on lunch. I asked that the supervisor call me back after lunch, it's now 14:07pm and I am still waiting for that call back.