Absa debit order

On 2 May 2018 there was a debit order on the church account for the amount of R4134.73. We went to bank and they could not tell us for what it was, but they are sure it is a Absa deduction. The clerk phoned head office and they told her that it is a penalty because we went in the red and we did not have a overdraft facility. Absa deducted the normal monthly internet banking fees and the other fees. The description for this deduction is : "UNAUTH DR BAL FEE R4134.73 ODL CAP. They told us they cannot reverse this debit order, and they can not help us. We went to the Modimolle branch in Limpopo. This debit order for what ever, resulted that we went in a overdraft and then all our other debit orders did not go through. Who can we contact please.