Auto and General Debit Account before Contract Debit Date

More than I have complained, Fidelity Auto General debits my account on the 13th or 14th each month, and not the 15th as per contract. This happens even if the 15th is on a weekday. I wasted more than R100 on airtime to sort it out. They continue debiting before my pay date. I have sent them emails. They assured me it will be rectified. For the past 3 months, they have been debited again before the time. This results in my account being in a minus, which negatively impacts my credit rating. I want to alert people to be careful when choosing Fidelity Auto & General.