car wont start

I just bought a new car and first day I was driving it
home, it was driving good to seemed as no
problem wrong with it. But as I got home and
turned it off and tried leaving somewhere again it
wouldn't start. Nothing wouldn't even turn over,
engine light turns on. Took it back to the
dealership three times and they replace my battery,
started coolent system and couple other things
dealing with the fuse box. Still does it and we took
it couple other places and they don't even know
what's wrong with it.