Un-authorised trip charged for.

I booked a Trip from Modderfontein to Greenstone Shopping Mall on 12 December. The passengers were taken to Greenstone mall and dropped off. The driver then proceeded to take my trip to OR Tambo airport and charge me for the trip. It ended up costing me R187 for the trip that was supposed to be R69 When I queried this on the Uber app, i was told I am not elgible for a price adjustment