I purchased a Tirreno Razza 2.0 at performance bike last wed.
On thursday I went there and had them install a couple of armadillo tyres, and the mechanic had a nice youg sales guy install it (not a mech). He also loosened the brakes. They were both super nice.
Fast forward to this morning: on the downhill I hit the brakes and there is no rear braking
So I had a very light crash against the pavement. I scraped the pedal (don't care) but also my shimano 105 derailleur (Do care! ) and also the right handlebar )....
So I came in to performance this morning. The mechanic checked it out and diagnosed the Shimano 105 to be fine. He also tightened the brakes. The manager of the store gave me a carbon water cage (which the mechanic installed) for my troubles.

I feel I've been had. But the guys at the shop have been nice (if incompetent as far as the sales guy wanna be mech. was concerned), and I don;t really want to go through the hassle of (1) getting my money back; (2) searching for a new bike elswhere (I really like this Turreno).

Any advice on what I should do? Was I "had" or am I acting reasonably?