Had to replace my cluch, aggrieved at issue not showing up at service 2 months earlier

Okay so I just had to replace my clutch to the cost of £1300. My car was serviced on April 1st at ATS they didn't mention clutch failing, a month later I took my vehicle to ATS where they diagnosed my problem (clutch is gone) and advised I speak to my dealership. I immediately called them, booked an appointment to get a diagnosis from them. That happened last week, I was hoping it'd be covered by warrenty but unfortunately the other day I was told it was wear & tear and it wouldn't be covered. They also said it wouldn't show up on a service check. My question is, shouldn't ATS have alerted me to the problem? I felt the clutch go pretty much immediately after the service but I put it down to other things (stupidly, I admit). Car is 2 and a half years old, Pegugeot 207, I've been driving it safely, the clutch surely shouldn't be going now should it? Kinda clutching at straws here, no pun intended, but any advice would be gratefully recieved.

Thanks.