I have set my homeloan debit order for the 25th every month but to my surprise AGAIN I have been debited early making my account be in the negative!!! I have opted out of the ridiculous campaign but it still happens

I have set my homeloan debit order for the 25th every month but to my surprise AGAIN I have been debited early making my account be in the negative!!! I have opted out of the ridiculous campaign but it still happens. I will be charged close to R150 for this by my bank. Tell me why I am debited today on the 22nd??? Just switch of this debit order now!!!!!