Thanks for all the input. It's obviously a sore point with a lot of people.
I don't know where I stand because when I first told my boss I was doing the exams, they were all for paying and cutting my hours to give me time to study.
Then when it came to paying I was given the elbow and took out a personal loan. And now I've paid for them, the boss has again become interested in getting me to work for them when I qualify.
So I'm addled now regards study leave and because 3 of our revision days fall on a work day, I'll need a total of 13 days leave.