ISH47:
I just finished another survey, this one taking me almost 30 minutes to complete, and on the last page before I get my credits it tells me the survey is full and I get nothing.. This is about the 3rd or 4th time this has happened to me and I know I'm not alone.
When you contact them , tell them that you completed the survey .When redirected to next page , you got a blank screen , and didnt receive your credits . It works for me , every time . Leave out the part of the survey being full , if you want your credits . :-)