No; mine does that too. She grabs hold of one of the pellets, and then spits it out. They're probably too hard for them to eat at first and need to be softened by the water before they can eat them. By the end of the week, my fish has eaten all the pellets; she just can't eat them all right away.
All my fish spit out their food when they're full. A Betta's stomach is about the size of his eyeball, so consider that with how much you're feeding him. How often are you feeding him? I fed my Bettas a pinch of food every other day and I've had a few live as long as 4 years on this. However reading up recently I see a lot of professionals feed once a day and then fast for one week.