Well, I have been there and there is not much that can be done, I actually got declined one the other day that was paid 2 months ago and was on the pending to cashed out. See FC has no control over anything it is the people that makes the survey the one that pay.
As a suggestion, you should finish your survey, and when the page says, you have been credited or Congratulations, leave the page open for at least 10 minutes , or until you see the payment on your account, sometimes they take a little bit to credit. Also clear your cookies every time you do a survey and be patient it will get there for you.
Good luck