How small are they? Post a picture.
If they are real small they might not be ready or have been conditioned to eat flake.
Nm I see they are only an inch.
You might want to go get some brine shrimp eggs and hatch them out so they can have something to eat till you figure this out.
I also suggest you get ahold of al the webmaster here and buy a small package of his fdbw and try feeding them those. My fry ate them first time I dropped them in the tank.
Whatever you do you need to do it quick.
I would get to hatching some brine shrimp real quick.