MacBook Air less than a week since I bought and it’s keys are loose and coming off

Terribly disappointed ! Keys are coming off.. bought last week and when get it to service Center, they said need to replace whole keyboard ! I can’t belive this ! Trusted and Bought Apple for its build quality .. I didn’t expect this!

Why can’t apple give me a replacement ?? And after repair usually laptops are of no use .. the next repair will be on its way !