Line Brake broke while driving

Hi, I have a Hyundai Accent 2012, that I drive all summer long. I went to the
garage end of August and ask to have my car check to be sure it was safe on
the road since I was leaving for university.

The garage bill me 1000 (He did change the brake)  and changed some stuff
and told me I was good to go.
I drove less then 20 hours since then. But today , my car's line brake broke
while I was on the road and almost ran into a tree.

I brought it to the garage (towing) and the guy there said my line brake were in
a really bad shape.

I know a mechanician cannot look at every piece of a car. But I was wondering
if it was normal that he never mention/change my line break when I said to
ensure my car would be safe on the road.