"Artists Beware"

Yup, he's a thief all right. I'm sorry for your lost time, but go ahead and resell the commission; ie, specifically open for a commission slot from that body base, or perhaps a full ref sheet like another poster suggested. The unfortunate thing is that the more often people like this rip off artists, the less we artists will negotiate terms with anybody. In a perfect world, payment might not have to come up front, but as long as freelancers online are this unprotected, we have to be complete hardasses.