Charging more than the confirmed amount

I confirmed an order and wait uber because the amount was R81, the driver charged R123 for a trip after being lost for sometime. Uber said it was the standard price yet i took the same trip the day before and they charged me R90.

What is the point of confirming a trip I can afford, and choose to the wait period so i can save more, only for them to take more than I had agreed to and disregard the fact that their driver kept getting lost.