Unilateral Change in Debit Order Date *******

My reputation has been damaged. I have an un*****ed financial reputation at ABSA Wealth which now changed. I now have one unpaid debit order as it was supposed to go off on 31 Dec 2021 not 22 Dec 2021.

Just saw that my debit order bounced on 22 Dec 2021. My debit order is set for the last day of the month due to my salary only getting paid then, every month no exceptions. The authorization and debit order date was agreed telephonically when I took out my Clientele Health Plan. This date may NOT be changed unless authorization is obtained telephonically or in writing. I called the Clientele call centre on 28 Dec 2021 and requested a letter stating that they did NOT have permission to deduct earlier than agreed and will wait to see if I get this letter.