Change of debit order nightmare

Mid April 2015 I went to ABSA bank midrand branch to request chabge in debit order date(from 25 to last day of the month) for my absa personal loan account. For April,May, June the debit order kept on going on the same old date. I went back to the bank to check why and they said that the request was not processed yet on the system, but they will do it same day and refund me for the bounced debit order charges. On the 29 June they sent they sent a debit order and it went through fine, this is after a debit order that they sent on the 25th bounced. And on the 1 July 2015, just 2 day from the agreed date, they send another debit order, with amount to double the installment. I visited the branch because some of my debit order have bounced because of this. And I was being assited by Mandela, for an hour and half I had to stand at the enquiries while he tries to help me, but he was unsuccessful with all the call he made and I walked out tired and helpless. My loan account was nit in arrears and they can'take explain to me why 2 debit orders in 3 days of different amounts. This is a nightmare and I don't know what to do.<br>