Thats completely unacceptable.....an old school mechanic can measure resistance of sensors to further confirm that a sensor is defective.
Sometimes, just contamination in a sensor connection or even damage to the reluctor ring (if seperate - e.g. not part of the wheel bearing) can cause fault codes and replacing the sensor is meaningless.
I would take the car to a good 'old school' independent garage who can diagnose the fault correctly