I read through your thread, and I am so sorry this has happened to you.

Over the years I've gotten a lot of good ideas about jobs and job-hunting from the book What Color is Your Parachute? -- I believe it's that book that suggests when you don't get the job (or get to stay on in your case) that you ask them why and what was it that you needed to improve. You might have to be a bit of an actor to do this (hiding how you really feel), but you could either go in or call to speak to the one HR lady who was so upbeat about your performance and let her know that you are confused since it seemed like you were doing such a great job and every one seemed to count on you, etc. Tell her (if you can do it without getting too emotional) how much you really enjoyed working there, how disappointed you were that you were not kept on and then ask her if she could give you any advice on what you might have done differently that would have improved your chances of staying on at that job.

You never know -- those six people who were kept on may have known the manager or had some other unknown connections. It may not have been anything that was 'wrong' in what you did.

At a minimum it seems they should at least be kind enough to give you a nice written recommendation.

Again, I know it must really be tough to have to deal with being cut off like that. These ideas are ways (perhaps) in feeling less helpless about what's happened.