Debit Order date change impossible?

I have taken Vehicle Finance with Absa, and they are refusing to change my debit order date.

I only get paid on the last day of the month and they are trying to deduct funds from my account before I even get paid.

Their response is they cannot move my debit order date from the last day of the month to the first day of the month as the day my Salary is paid in to my account is the same day the debit order has to be on.

But my salary only gets deposited into my account on the last weekday of the month late in the afternoon, But Absa Debit order already bounces in the morning.

If the Debit order is moved to the 1st of every month as per ALL MY OTHER debit orders, there would be no issues.

There has to be some grace period this is ridiculous it is only 1 day difference between having a debit order bouncing and the funds going off with no problems.