iphone 5s replacement swapped by Apple yesterday is also faulty - loose on/off button

Yesterday I attended a Genius appointment at the Apple store in Regent Street London to get my first iphone 5s replaced since it had a loose glass front. After being offered that it would be repaired, which I declined and asked to speak with the manager, the 'genius' rep agreed to replace it. The replacement arrived in a small box from the basement and he insisted it was new.

Less than 24 hours later the replacement iphone 5s is not rattling with a loose on/off button. When you move the phone, tap near the top of the screen or adjust your grip in any way, the whole phone rattles loudly.

This is worse than unacceptable from apple.

I also think the apple rep gave me a faulty phone knowing that it wasn't new.

I have totally lost faith in Apple now, a shower of chancers