If you can't get your money back we're probably going to have to go a little ghetto to get this thing usable.
Okay under where your hopper is there should be a silver (not sure on colour) cover, if you undo it there should be one of these underneath:
http://www.jtpaintballparts.com/131032-000-Orion-Ball-Stop-p/gp571.htm
trouble is they are out of production. The function of this part is to hold one ball in the breach and stop the rest feeding in. If it is missing I would try taking a small oring and trying to sort of wedge it under the cover so its sticking into the breach a little bit then seeing if that will hold a ball in there and not get destroyed when you fire the marker. you could also try part of a thicker oring that would stick out until the bolt pushes it into the side of the marker.
Okay under where your hopper is there should be a silver (not sure on colour) cover, if you undo it there should be one of these underneath:
http://www.jtpaintballparts.com/131032-000-Orion-Ball-Stop-p/gp571.htm
trouble is they are out of production. The function of this part is to hold one ball in the breach and stop the rest feeding in. If it is missing I would try taking a small oring and trying to sort of wedge it under the cover so its sticking into the breach a little bit then seeing if that will hold a ball in there and not get destroyed when you fire the marker. you could also try part of a thicker oring that would stick out until the bolt pushes it into the side of the marker.