Poor client service by mazda kelston motor group queenstown

The service I received at kelston motor group ford/mazda queenstown is so inefficient multipletimes, I made a booking on 3weeks advance and I brought my vehicle in for service 4hours later to be informed that the service parts are not on stock after driving a round trip of 320km, I wonder why the service manager didn't inform me on time that they do not have stock before I drove all the way to KELSTON MOTORS QUEENSTOWN both instances I had to go back home with service incompletely done, I suggested the management to stick to Ford and let go of servicing Mazda because their service is poor or this is because ******, personally I wouldn't recommend them to anyone POOR SERVICE AND CLIENT COURTESY if I had a way I'd sell this car