Absa

I have a absa life insurance with Absa for many years ,after changing my debit order date and bank I have this problem. My insurance debit goes off every month, but from the 19 of every month it's says that my insurance is in arrears. I went to the bank they said everything is is up to date, hence its not. I even logged a complaint they said it's up to date , I even have emails where they say it's all in order. But why does it go into arrears when I pay every month . What if something happens then I need to struggle for payout. I tried paying the arrears amount on the app , cause I don't want any issues, still can't. Only after the 20th..so what is my solution really. This is unacceptable.