MY INSTALLMENT INCREASED WITH R1800.00

i was doing a claim this month on my service plan, they called me and said they need to cancel the old one and create a new policy that will cover the km on the clock i agreed as the car was in for a service. after 2 day another once call and say wrong information is recorded under my profile. they recorded that the car is petrol but the car is diesel. i dont understand how can you make this mistake as the are the one financing the car.

today again i get another sms which shows that my installment went up by R1800.00 i dont understand how and why. i called them the guy said there are three policies under my profile i asked if they can remove one as this is wrong or duplicate but i have to wait 21 days for their mistake. this month there are coming for more money in my account. the money which will never be refunded. im disappointed in this.....