How do you get your AS papers rechecked?

As the title states I have taken my AS exams and they have gone horrible beyond my expectations horrible. My maths which i had thought for sure i would get a very high A and my physics have turned out to be B and C's. I can't do anything but believe this is an error(probably because my handwriting is bad). The only subject which i did not study much for is the only subject I have an A in i was expecting a lot worse it makes no sense...
How can i send them to be rechecked?