First off, don't posts in all caps, people think its rude.
Secondly, your betta can go pretty easily for a week without food. Give him a few days of not eating and add in whatever food you have been giving him. He'll probably eat it up.
Some bettas, though, are a little more picky and you'll have to experiment with different kinds of food, including pellets, flakes (though most bettas don't like flake food) frozen or dried food, and live food. Your petstore will have a wide variety of these. Although for slow moving fish like bettas, it's usually better for the food not to go flying around the tank because of the filter, I've noticed some fish pick up on the motion and that clues them in to whatever it is floating is potentially edible. You might want to see if some motion on the part of the food (filter, you swirling it around, or it falling to the bottom) clues the little guy in. Just make sure you don't leave any food in there to foul the water.
Bettas don't eat a lot, they are fish and tiny ones at that. An every other day schedule is probably a good one. I've been a sucker (the little guy comes to the front of the tank and demands food, practically), so if you feed your betta everyday, make sure he fasts one day a week.
We get attached to the little buggers and give them far more food than they would get in the wild. Being cold blooded, fish need far less energy than we do and in nature, most of a betta's meals would come from bugs getting stuck on the surface of water (which doesn't happen twice a day or even every day!). He'll be fine, you shouldn't worry
Two days is not a big deal. A lot of bettas won't eat for that long when they've been introduced to a tank. Don't bother feeding him for another couple of days and then try. If he still won't eat, then try and experiment with other kinds of pellets or bloodworms.