Help! My betta can't eat!?

I just got my female betta this morning. She was healthy and energetic and swam all around her bowl. I tried feeding her just a few minutes ago. I put 3 pellets in the bowl. She lunged for the food and popped it in her mouth, then one second later, she spit it out. She then lunged for the same pellet and popped it in her mouth and she kept on spitting it out. She keeps on popping in her mouth and spitting it out until she mashes the pellet up until its like flat and the pellet slowly falls to the bottom of the bowl. I don't know what's wrong, but I doubt its the type of food. I use the Top Fin Color Enhancing Betta Bits. I'm freaking out since this is the second fish I've got since yesterday and I don't want this one to die also!