I have had similar experiences with surveys. This has happened on Fusion Cash as well as other sites. I have spent a lot of time on a survey only to get a message that I did not meet the profile. when I thought that I must be at the end of the survey. I was expecting to get a congratulations and instead got a sorry. Other times, I have completed a survey and submitted only to get a message that I was Over Quota.
Fortunately, this does not happen most of the time but it is really frustrating and disappointing when it does happen.
Whenever you begin taking a survey, you are taking a chance that the survey will close before you finish or by the time you submit, you are over quota. Other times, you may be going too fast or you might make an honest mistake during the survey kicking you out.