MFC pathetic customer service

I bought a new car middle October. I emailed MFC on 15 OCTOBER 2024 to change the debit order date as from November to 31st of each month. I receive a sms today on 22 November saying debit order due 26 November 2024. I phone them to ask whats going on with the debit order date saying 26th, when I changed it 6 weeks ago and received confirmation of this transaction. They can not explain, say they will log change of debit order today so it will be corrected from the end of December. I am so so so so disappointed and livid! What's the use of doing this in due time and nothing happening as requested??? Why do they have a customer service email??? And no explanation??? Pathetic!