BMW customer service reps need more training

Last week Friday , I called BMW to book for my F30's timing chain to get changed. The lady at the service centre asks me why do I want to change it and I reply " you recommend the timing chain to be changed at 160 000 km". She kept on asking what is the car doing and I kept on repeating myself and telling her it needs to be changed as per BMW recommendations and there's nothing wrong with the vehicle!