MFC extending vehicle finance *****ulently and without consent!

The balloon payment for my vehicle is due on the 15/12/2023. I have received an addendum to my agreement stipulating a revised repayment plan and 18 months extension to my contract WITHOUT my permission. When I contacted the MFC, I was told that their system was already updated with the re-structure and the debit order for the new agreement will be deducted on the 15/12/2023. The consultation further stated that I can settle the account however the debit order for the new instalment will still run on the 15/12/2023. I don’t understand what kind of *****ulent financing agreements MFC is running. This is unacceptable and total disregard for consumer rights.