Uber and their additional charges

I would just like to know where can Uber be reported in South Africa, because this is becoming ridiculous, how is Uber getting away with changing the trip amounts? I have had many instances where I book trip, like last week the Trip amount was R157 and then they tried to deduct another R167 from my account, as they wanted to charge me an R11 extra. So what they do is, as soon as you book a trip the amount shown on the App gets deducted from your account , then a day or two later they deducted another amount from your account that is slightly higher that the amount of your trip, but then they do a correction and don't refund the entire additional 2nd amount that was taken. How do they decide after the trip that you need to be charged more?? Imagine if a taxi does that. Are Uber even being regulated in South Africa??? If yes, then who regulates them. Nowhere when booking a trip, is there any indication that the trip might cost more.