Just found this thread
which seems to be relevant. Here is a post from it.
"He probably just starved himself to death. Bettas don't need much acclimation. IMHO, he didn't eat because of the strange foods and tank size. Most Bettas are imported from Southeast Asia where they were raised in ponds mostly eating live foods. Sometimes, they wouldn't even eat the frozen blood worms. When the tank is too big and the fish doesn't know what to look for, it'll be harder to get him acquainted to the new foods. When the fish won't eat, you should keep him in a smaller container where he can easily see the food all the time. After he got used to the foods and to you feeding him, you can move him into the big tank. Then he'll also associate you with food and when he sees you he'll just come right up to eat. We've had problem like yours and this has worked for us."
Also something I just realized. He did like some live brine shrimp that I gave him the other day so I think I will get some more of those tomorrow and see how he does with them. I might try the soaking of a pellet in garlic oil as well.