if you need to contact david or jacob, just use the " contact us" link at the bottom of all the pages of sharecg. i never had any problems getting a reply from that.
hope this helps. i am sure the fact that people are not getting paid what they are due is a matter of concern for all here.
http://irishlostboy.deviantart.com/gallery/
http://www.sharecg.com/pf/irishlostboy