Uber is a ripoff

I am so over Uber. A trip that should have cost me R67 ended up costing me R100. How is it that you can use Google maps to give the almost exact time that it will take you to get to a place even in traffic but Uber cannot do this. I have Uber one and I still have to pay ridiculous prices. This is in normal traffic. I don't get how their business model works. They should have a price and stick to it.