Wesbank debit order date change without any communication or approval

I have been financing my car(s) via Wesbank for more than 15 years now. I have NEVER missed any installment. Not once over all these years. My contract agreement debit order date with Wesbank is 23 of each month – has been for ALL these years. I emfisize – SAME date, NEVER missed a payment for all these years. My Nov debit order goes off as per contract. WHAM – same debit order goes off on 14 Dec 2023. No warning, no agreement. I take a screenshot, since I want to call the bank in January 2024 when I am back from leave. Early February 2024 I get a call from the bank that I am in arrears. I was surprised as I saw that the bank actually took my installment TWO WEEKS early. I need to note, that I am with the same company for 17 years and have always received my salary on the same date. So CLEAR trend here. Upon reviewing my statement I see that they I reversed the early claim and didn’t take the installment on the 23rd AS PER CONTRACT AGREEMENT FOR YEARS! What are you thinking WESBANK? I have been a good client for years! You cannot tell me where you received the APPROVAL to take my installment EARLIER, then write it back, then not deduct it on the AGREED DATE? You are a big company and will most probably ***** me over but I am just in shock of how you treat me. This for R4000!?!?! I have a money tree where I can just quickly get the funds for you hey!