Why did P&O use a shuttle bus on our cruise to Amsterdam?

The company moved the berth of our cruise ship to a port 30km away from the cityA group of us booked a four-day P&O cruise from Southampton on 22 March, docking in Amsterdam early Saturday until late Monday giving us direct access to the city. Last month, we learned the ship will dock at a location 40 minutes away by shuttle bus. P&O did not contact us about this. Anyone wishing to take three daily meals on board (part of the package) and spend the rest of the day in Amsterdam, would spe