I had the same problem getting to the actual survey. I e-mailed to the contact address at Anabus.com. Got a message back from a michael_kutch@anabus.com stating that I had qualified from the screen and giving me a unique passcode and link to the survey.
Get to them right away as they were only needing 200 responses and he said they were close yesterday.
I completed the survey and donated the $50 to this site, as there is an option for that at the end of the survey.
Good luck!