Insimenator.org

The social worker took all of my 4 kids. I phoned adoption several times but I they denied.
Will I ever get those kids back again???

As far as I know, there will be no way for you to get them back. They'll be available for adoption by other families, though. If the adoption agency is refusing your request to adopt, then they either have no other kids, or you've had too many kids removed. If you have the Free time EP, then you can avoid having your kids taken away via the "Plead with Social Worker" interaction.

As a note, the Social Worker will come when: 

-When the child's needs are too low
-When a child has an F in school
-When a child is left home alone
-When a child is too hot or too cold (only with the Seasons expansion pack)

One way around it, I think, would be to make a new family with no kids, move them into a house and have them adopt your kids (if they aren't adopted already). You can only adopt once a day. When they have all your kids, move them out of that house and in with you. The kids will automatically be given new Astrological signs and birthdays (just so you're aware). Now, I'm not sure of this, but think you can have the adoptive parent move out and leave the kids behind.

Thank you very much. I've the EP but couldn't plead. But I think I'll make a new family and move them in.
 :D

I believe the "plead with social worker" interaction is an aspiration benefit you have to unlock first.

Yes you can by getting one of Inge's teleporters at: http://www.simlogical.com/sl/Sims2Pages/Sims2_Teleporters.htm

You will need to find them in one of the townies family.

I got a kid back by having her adult sister make the adoption call, then fixed the relationships with SimPE. 

They dropped her grades from A+ to C too.  Barely got her back to A+ before she became a teen!