sinking or floating? I got mine to eat Hikari sinking pellets... but it would only eat the ones it saw still drifting down, once they hit the bottom my 4line picked em up... I would try some flake food... thats the first thing mine took. Then try some market shrimp or mysis shrimp or beef heart... other ideas would be live worms, like earthworms or meal worms. They would still move so it may help entice them into eating.
Another thing is if you havn't had them for very long, and they got beat up by a gar, they may just be on a catfish hunger strike and need to settle in. At that point you have three choices...
Continue offering them a wide range of foods and remove all the uneaten food until they find something they like or decide to eat
Fast them/starve them for a bit, make sure they are hungry, then begin feeding them what you want them to eat
OR force feed them if it come to that. Blood worms or other thawed-frozen food in an eyedropper or turkey baster being squirted directly in front of their mouth usually works... but I don't know that I would try this until you are certain they are not eating.
One more thing is that they may only be eating once the lights are off. I've had several cats do that too me... So I have to start feeding them right before I turn the lights off, so theres food there when its dark for them to feel comfortable. You can slowly wean them off the darkness, and train them to eat with the lights on... just takes time