I checked the "screen outs" over the last two weeks to see if there are any inconsistencies. It looks like the main reasons for getting screened out were:

early screenout
over quota
client term

I'm not sure what those mean. But they also had a few "quality terminations" and "already do internal"

For quality, they must not have liked something in your early answers in terms of consistency? I wonder if "already do internal" is them catching that the survey was for a company that you are already doing surveys for directly in some way? Either having an account with them or doing their proprietary routers?