You have to understand that some offers pay for some people but not for others, so to post one and say this one does not pay, just because it did not pay for you does not mean they don't pay. Admins can look into the rate at which the offers are approving and see if something need to be changed, but posting names of offers and claiming they don't pay is like biting the hand that feeds you.
Ok, but at the moment when I see offer and actually do it, I don't know that offer let say limited and I will not get paid. I think it's not fair. Why should I waste my time?
I am not trying to be rude but no one is asking you to "waste your time" here. But in case you didn't know, if you publicly complain about offers in the forums and the sponsors see it, they will punish FC by pulling their offers away. That would punish the 95% of us that are perfectly happy with things here. I have a constructive suggestion for you. Instead of doing so many offers that won't credit for you, why don't you focus your time on getting referrals. You can earn a lot more that way any way and then you won't be frustrated by offers not crediting. You will eventually run out of free offers, so graduate up to the next step and try to get some leveraged money. Since the majority of people seem to get credited, you will be showing your referrals how to earn money free and you will be a hero in their eyes and you will be earning money in your sleep. Then do the .15 daily and a few other easy offers and cash out every few months. Look for other opportunities online also.
My advice is to branch out and find your niche. If you are not willing to be persistent and work through a learning curve and some frustration, then earning online may not be for you. There's always the want ads.