Wha buh? A bonus cel?

I received my package from Anime-Gambit. Imagine my surprise when I saw not two, but THREE, cels! I only ordered two! I fired off an e-mail asking but I haven't received an answer yet. I wonder if it was a freebie or a mistake..
The cel in question is a gorgeous cel of Celestine from AMG. Actually come to think of it, he DID ask me what I collected after I paid him. Hmm. o_o