Unauthorized debit orders after arrangements were made

I had a situation and my debit order did not go off on the 1st January. I phoned Cell C and arranged for a Double Debit Order on the 1st February on which they agreed upon. Yesterday was the 3rd time that they debited my account since my arrangement with them incurring more reversal costs on my account, that is 3 x R115! Total of R345.00 that my account are in a negative.