Unauthorized and incorrect debit orders

This company is extremely *********. I started my contract in April 2022. They have been debiting my bank account with the incorrect premium. I called them so many times and they promised me they will fix it, but again today they debited my account with the incorrect premium. On top of that I also received a calls beginning of June to say I made arrangement to pay 3months in advance and the amount is R451. After numerous calls and emails explaining to them that I never made such an arrangement they went and debited my account today with R451 without my permission. I am soooo angry at this company.