I know this vraag is old but I can help you. u need to have your cat "full" and "quenched" and leave the DS for 40-50 mins. Do not even walk in front of it otherwise the facial recognition will recognize you. Then come back to it and tap the "whistle" button. Your cat should come running in with a gift.
This may not be helpful, but one reason may be that u need to keep the pet clean, quenched, and full. u also have to pet it at some times, of it will get a bit lonely. Try taking it walking of going to the park, too.
