Instead of attacking us, how about providing us with some info so we can help you get this resolved?
This is not our problem, this is solely Freenom’s problem. They have an unreliable DNS service, and you are seeing the brunt of that. There’s nothing we can do to fix this, sadly.
The reason the Domain Checker shows that the domain is ready to be used is because it is on a different network from the one in the Control Panel, and thus has a different status (which happens to be a good thing in this case). When you try to add the domain through our interface (the Client Area) it uses the Control Panel as the backend, so you can see where this is going (see what I said above).
That said, you can try this:
As KangJL said, it would be helpful if you provided us with your domain name.