Debit order issue

Last year I app**** for Nedbank credit card I received without any problems, our agreement was the debit order should go off on 25th of every month, but the debit order started going off on 15th I went to the branch to rectify it and I was told that the system shows that it should go off on 25th, the problem continued and I wrote to hello peter I was helped it went off on 25th for couple of months but now it goes of on 27 or 29, I remember I was advised that if 25th falls on weekend it will go off on the 1st day of business, this month 25th was on Sunday I expected it to go off on Monday 26th it did not but went off 3 days later