Birds fed these diets are on an imbalanced seed-based diet. However, if the seed was left until all the seed was eaten, including the granules, then the birds would get complete nutrition. It can be hard to convince your birds that pellets are good for them. Have two feed containers, one with pellets and one with seed. Sprinkle a few pellets over the seed so that the birds recognise them as being food.
Every second day remove the seed from the cage, leaving only the pellets.
Continue to feed the fresh fruit and vegetables daily. It still may takes several months for the bird to try the pellets. There are many different brands of pellets and crumbles on the market. Your bird might accept another brand with a different shape, colour, smell or flavour. Try feeding the pellets out of the cage.