You betta is training you! Haha. But don't worry, bettas won't starve after only 1, 2, even ten days without eating. A healthy betta can easily go two weeks without food. Keep offering a couple of the pellets or guppy bits (as treats) every day and he will eventually get hungry enough to eat them.
Just make sure to remove any uneaten food.
If he really protests and after a week or so hasn't eaten even a bit, see if you can get some garlic juice. Put the guppy bits in a couple drop of garlic juice before feeding. It will probably be like a little shark feeding frenzy!
Remember that the tank your fish lives in is his or her's whole world. Ask yourself this question, and answer it honestly: would you choose to live there?