Have you debugged and traced through the code? Are the images sucessfully loading? Are you actually drawing the sprites? Trace through and find the section that's not working and then ask specifically about that if you still can't figure it out. "Here's all my code why doesn't it work?" posts are hard to answer.
Edit: It looks like you have error-checking code for loading, so I'd look at wheer you're drawing.
Edit: Also, iterating through every image everytime you want to draw one is terrible. Like really, really slow. What are you actually trying to achieve with this class?