Wrong Debit Order Date every month different date.

Standard bank has not given me feedback as to why they deduct my debits order on different dates that were not given to them. I have a Term loan with Standard bank and when I did a application they asked me when my pay date was and I told them it the 27th everymonth. I have been banking with this bank for years and my pay date has never changed. Last month I received a debit order on the 21st August before payday, this takes you out of budget because you expect debit orders to go off on your pay date. I reported this and no one came back to me. Again this month September this morning a debit order went off today is the 16th September my pay day again is the 27th monthly. Every time Standard bank says they will investigate and come back to you they never do, no personal touch when it comes to their loyal clients how do you not track and know the pay date of your client. I spoke to banker Gladys Mashiso (very nice lady who was friendly and was able to assist) ref number *** who confirmed they will investigate and come back to me.