FuelCell Energy Inc (FCEL)

[J-fire]

Hello my fellow FCEL investors, congratulations to all of you that stick with FCEL riding the roller coaster all year long.

I sold some of my shares 2 days ago. Something odd happened and I am still confused. So I come here seeking some explanations.
I wanted to sell 5k of my FCEL shares that I purchased 1 years ago, however my broker only allow me to sell 4.5k, I can see the rest of 500 shares still in my account but just couldn't sell them. I thought 'fine then, I will just sell 4.5k'. So I placed an order to sell 4.5k. But it turned out I still sold 5k of my shares, the extra 500 came from the lot I bought on other days...I contacted my broker and they didn't reply me yet. But later today, I found out the 500 shares were assigned to the lot I ordered 1 years ago.

Can anyone give me some hints about what is going on here?? Thank you very much!
-Jfire