iPhone 6 Plus Loose/wriggly Volume + Power buttons

Within 24 hours, I have had two iPhone 6 Plus.

The first time for me to splurge a big amount of cash on an Apple product, given that I have always been on a contract for the last few years. Very happy to be able to get it very soon, but problems keep cropping up. You may think this is trivial but I do believe a phone device that's advertised at £700 should NOT be manufactured to have rattling buttons/noise, especially when Apple claims that how meticulous they are when it comes to designing an iPhone.

Both iPhones have loose buttons and this includes its volume buttons, switch button, power button. A replacement was given without hassle in the Apple Retail Store, but the same issue exists, unfortunately. Worse still, I can somehow hear the rattle if wobbling the phone slightly. Now, this sounds like a carelessly designed or cheaply built product.

I guess this is similar to having a brand new car, any part/component that rattles unexpectedly sounds broken to me.

I understand that this is all subjective to one's definition of "sturdy", but I don't think I should have rattling buttons on a brand new phone.