Your switch is wrong, and they are chars, not numbers. There is another problem with it, but I'll let you to figure it out yourself.
This comment is hidden because it contains spoiler information about the solution
That's a problem with your code, not with the kata. Expected value is ok, what's wrong is what your function returned, if you want some help, post your code and mark your post as having spoiler content.
Sorry, but what's the issue exactly? I've passed the kata and I can't find it.
C++ bug with number 1 to letter I
Not an issue.
Don't convert a string to uppercase when you're not asked to?
'J. K. ROWLING - HARRY POTTER AND THE PRISONER OF AZKABAN'
'J. K. ROWLING - HARRY POTTER AND THE PRISONER OF Azkaban'
Why only Azkaban is in small letters??
Why is this an issue? None of those letters is one of the three you need to check for. So you can left them as they are. I know you say for consistency, but nowhere it says all letters are going to be capital ones.
Error in test, will only work with all toUppeCase except in one test.
Azkaban should be AZKABAN for consistency.