Uber is very professional company. Any customer complaint is acted upon instantly.
Recently I was billed wrongly by uber as the gps system of the car had some problem leading to mistakes in charges. It was automatically rectified by uber instantly refunding the miscalculated amount . Once the driver said that he cannot come after receiving the booking and I booked another uber and I was not charged anything extra for cancellation of the earlier booking done within 10 mins of earlier booking.