Nedbank are ****s!!!! Taken double debits with no consent,

Nedbank once again double debited my account. They swore that this would not happen and yet it happened again. Two months in a row. I called them after this had happened. I litteraly begged them not to do this as it puts me in a he'll of a predicament. And once again. They **** to me. Telling me to accept the debicheck mandate. Promising me it will not happen. Last month they did not even have the decency to refund the whole amount they took without my consent. It also trek nedbank 12 days to refund me less than half the amount and query. I cannot leave this to happen again. There must be someone higher up I can speak to.