Was I or Am I Being Taken Advantage Of / Being Screwed Over?

I did a music video for a small production company and a label signed band, which was directed by a director who's previous work had appeared on MTV. Myself and one other actor were featured in the video. I never signed a release form or anything actually, though it was understood that I wasn't going to be paid to be in the video. However, I was never told that there could be a chance for profit after the video would be made. I was also never told that the video had been completed (did the video in June 07, it aired online in Sept 07), even though I was promised a hard copy. The video is on the production companys site, youtube, and my boyfriends sister just saw it aired in American Eagle. Apparently, the label is also creating a music video compilation featuring the video (to be sold). Do I have any right to ask for a share of the profit? Am I being exploited? If so, what do I do? If not, why not?