harmonicanarchy

I think you're the one that needs to consider growing up here, not your teacher.
 
It isn't primary school. It's college. It's almost the real world. You take a paper, entering into a contract.
They tell you when the tests are going to be, so if you want to pass the terms, you'd better prepare.
If you fail, you fail. 
There were probably a lot of students who didn't pass. The teacher has no obligation to let them all retake the test. 
I'm sure a lot of students who passed would love to do the test again too. Should they get another chance to improve their grade?
I don't think so...
 
Harden up.
You do well in some things, bomb in others.
That's life.
Just be better prepared for next time.