I am not sure, But WGT probably has the right to request certain free credits surveys off there website, if there not paying out free credits to the participants. But I do believe WGT gets a Kick back in monies from everyone who clicks on a survey weather it be free or paid. So in my opinion WGT has the better end of the stick here.
All surveys as equotes, samplicio and the one for auto insurance I have never recieved credits for it. I gave up trying to contact trial pay. Now when I get quotes in my email I put it in my spam folder.