Debit order on the wrong date

Capitec debited my account on the 20th of March when they are supposed to only debit me on the 25th. When I phoned them the collection agent stated that I am in arrears, which I know I am not. I told her I cannot be in arrears. She put me on hold and came back saying that I am not in arrears she didn't look at my statement properly. I paid R2000 into my capitec account and they took all my money with this "issue" they apparently have. When I asked her to reverse the debit order, she said she cannot help me I must call later to sort it out.