You explain to your case worker that you and your children are in DIRE STRAITS RIGHTNOW and that he has a good paying job and is throwing money away left and right when you can't even buy diapers for your NEWBORN BABY. Remind her that you also have a two year old but can't put your kids in daycare so you can get a job....
Make her WANT to help you. Make her see that you are NOT a deadbeat just laying around sucking up welfare...they start to see everyone like that even though that is NOT the case much of the time.

YOU HAVE TO MOTIVATE her to get you what belongs to your girls.