A while back I posted a response that I received from e-rewards about this annoying issue. They took some time to explain that the surveys sometimes go out in waves, and it's entirely possible that by the time you receive one of those highly desirable 8 pointers, enough people have jumped on them that the quota has been filled even before you see your offer. Frustrating for sure, but at least it's a plausible explanation of why the instant kickout.