Let go

Who would I contact about the reason I was let go? Because I was doing better on my task ratings and everything! I even got a special project to complete I did so well, and thats where I think I messed up. I had entered my hours myself when they were going to do those bonus hours for me I guess. And that showed I had over 20hrs I put on there myself unaccounted for! I explained what had happened in an email back to them and got no response, and then was just let go a few days later. Who do I talk to? Any ideas? Or should I just move on?