No change to debit order amount after reduction in interest rate.

I have a debit order with Wesbank that goes off on the last day of every month.This month a reduction in the interest rate was announced by the SARB on the 22/11/2024 which was said to be effective immediately,so my expectation was that with the next debit order an adjustment would have been made to the debit order amount,since that has been the norm.If there is an increase in the interest rate I would notice the change with the next debit order having been increased.I called customer care to enquire why the amount is still the same even though the expectation is that it should have been reduced in line with the announcement made on the 22/11/2024 by the SARB.The consultant informed me that the change will only be made in the next debit order cycle which is December 2024.I am not happy with this practice by Wesbank which appears to put clients in a disadvantaged position.I do not understand why if an increase to the interest rate is announced then the change happens immediately but if it is the other way round, clients have to wait for Wesbank to decide when it will be convenient for them to implement the change to the amount.