Uber is constantly charging me unnecessary amounts

Uber is constantly charging me unnecessary amounts. I use Uber daily, for my business deliveries. And everytime I request a ride, the amount is different from the one deducted from my account at the end of the trip. Even when there is no waiting time. They are wasting my money and it’s so so sad. They are also extremely difficult to reach as they don’t have a helpline. It’s so frustrating. Especially for someone like me who spends close to R10 000 on their services monthly!