Fare adjustment double the fare originally reflected on the app

This seems to be a regular complaint and unfortunately I can now verify that it really does happen. Agreed to my regular 14km route in app when all of a sudden a different route is taken because apparently that's what the GPS said. Was charged for original fare I agreed to and received receipt and then about an hour later received an adjustment FOR TWICE THE AMOUNT OF MY ORIGINAL FARE. On enquiring this with Uber I'm simply told the driver experienced technical difficulty and with that in mind the trip was adjusted to actual km and time spent and the driver has to be compensated. That I understand, what I don't understand is why I must pick up the financial responsibility of R239 compared to R 114 when technical difficulties seemingly refers to equipment issues of some sorts and who does that belong to?