Uncommunicted expense

Took the car in to have the clutch fixed and was told the warranty might not cover and it was not. And the cost for repairs was too much and was not told I have to the diagnostic fee which was not communicated before, I asked why was this not communicated and I'm told it is standard on declined quotations, my issue is why was not told??? I feel this is unfair ambush and unfair treatment because had I know I would have told them not to do it.