Debit order still active

Telkom actived a debit order to the value of R79-00. When I requested a reason for this debit order they did not have an answer but was willing to refund me for nearly a year's deductions since I closed my Telkom account in May 2015. I thought they will arrange the cancellation of the debit order BUT they didn't. I cannot find anyone who is willing to assist me with the issue of the debit order deduction for February and March 2016. I do not have any control over a debit order they created and would appreciate SOMEONE at Telkom to find a solution, refund me once more and ensure CANCELLING the debit order.