Years ago, a professor agreed to write a LOR, but never sent it. Therefore, I'm not accepted in any school. What can I do? Years ago, a professor agreed to write me a recommendation letter.  So I applied to many grad schools indicating him as one of my referees.  However, I didn't find out until later that he didn't write the letter.  Thus, none of my applications were completed, and there were also substantial financial losses due to application fees. I was poor, so it was a big loss for me. 

What can I do in this case?  Could I find any justice anywhere?  I just felt hopeless when a tenured professor does something unethical (not criminal conduct); there is nothing a student can do.  

[added the following on June 24, 2014]

He recently became a faculty at the university where I am a student (He was at a different university before). I want to forget about what happened, but the damage was too much for me to ignore. And I feel anger whenever I think about what happened.

One remedy would be he takes me on as a PhD student, or provides funding so another professor can supervise me. However, my application was rejected.

I raised my concerns with the dean of faculty of graduate studies, and will meet one of the assistant deans soon. How should I approach this with him/her?
That sounds like a frustrating and discouraging situation.  Whether you have any recourse may depend on the system.  For U.S. universities, there's not much you can do, since applicants are generally considered responsible for monitoring whether their applications are complete and reminding letter writers.  However, these cultural issues might vary internationally.

One puzzling aspect of your question is that you describe the professor as deceiving you and acting unethically.  Without some specific evidence, I'd assume it was forgetfulness rather than deliberate sabotage.  Forgetting to submit letters is still irresponsible, but not as bad as intentionally not submitting them.

If you have compelling evidence of sabotage, it would be worth bringing to the attention of the university administration.  However, it's not clear to me what sort of evidence you might plausibly have.

If it's a matter of forgetfulness, things are murkier.  If there's a pattern of irresponsibility, then the department head might want to know.  On the other hand, a single incident would probably be ignored.

What makes this tricky is that professors get asked for recommendations in all sorts of suboptimal ways, such as a brief hallway conversation while both people are rushing to get to class.  It's easy to forget under these circumstances.  That doesn't make it right, and responsible letter writers will try hard not to overlook requests.  However, some circumstances make it more understandable than others.  If you do file a complaint with the administration, you should make the circumstances clear.  (But without evidence of dramatic or recurring irresponsibility, I'm not sure it would be worth the effort.)

Have you tried asking the professor about it?  It's too late to fix your applications, but you deserve an apology.  Furthermore, he may have forgotten about it so completely that he doesn't even realize this happened, in which case you'd be giving him a valuable warning that he needs to be more careful (and you might save future students from this problem).