$72 Uber ride became $180!!!

I took an Uber from my home to the airport, a trip I have made more than 100 times. I usually find Uber to be in the $80 range, and a standard cab is about $100. When I looked up the fare for this day, it showed up as $72-94 (about what I'd expect for midday on a Monday. When I got to the airport, the fare showed up as $72 and change. I got on a plane.

Two days later Uber added an additional $108 charge, with no explanation. When I complained, they responded that there had been a problem with the driver's GPS, and "estimated" the fare at >$160, a "discount" of $20.

Bear in mind that this is still more than twice the normal Uber rate, and $50 more than taking a private limo. It's also WAY more than the fare range I was shown prior to booking.

I have tried to resolve this through the app, and online, with no success. Has anyone found a way to get Uber to take responsibility for this kind of mistake?