Cab drivers dramatically boosted profits while decreasing driver pay? This goes way beyond increasing prices. Uber both increased prices and decreased driver pay at the same time. I used to driver Uber to make extra cash. They usually took about 16-17% and I made $25-30/hour (before taxes and expenses). Now they take more than 25% and I make $20/hour before expenses so I only drive when I want to have a bunch of conversations with random people

Cab drivers are by law (in much of Europe) required to have their prices stated on the window or inside the car, with surcharges clearly displayed. The driver must also have a valid id and license displayed inside the car.

Are you sure you actually rode a taxi and not some illegal or almost illegal rideshare like Uber which has no such regulations? If I were you I would have taken a picture of the car with the license plate and then reported them to the authorities.