To me it seems he might not like his new tank setup very much, and is just upset with you. I have had and have known Bettas who are very touchy about their home being moved around and have acted the same way. He might get used to it he might not.
If you want, what i would suggest anyway is changing the tank once more -not the water, just the decor- changing the water too much can really screw up the chemistry of the water and stress him out too much.
I don't know what kind of decorations you have in with him but I suggest plenty of plants and places for him to explore. NO plastic plants as they will tear up your Bettas fins unless they are super soft (and even then, i've seen them destroy finnage). My Bettas LOVE to hang out in the plants, so thats a good place to start. If you can find a Betta Log (
http://s3.amazonaws.com/tc-photos/11...ard/521971.jpg) he might really like that. I have one for one of my fish and he loves it. It took him a little while to figure out what it was, but now he hangs out in it and sleeps there and everything.
I also suggest buying some Stress Coat(
http://thegirlwithfish.files.wordpre...tress-coat.jpg), which also has water conditioner in it- so it's a 2 in one. He doesn't appear to have any stress stripes, but sometimes any loss of color can mean he's a bit upset. I would say about a cap full and maybe over the next few days half a cap. It's helped out my fish tremendously -i have 9 males- one of witch gets stressed out extremely easily.
Also, try looking for some bacteria supplement, it helps boost the immune system of the tank and gets the tank started on a better foot. You add that stuff when you do a water change, add your dechlorinator/stress coat then wait about 15 minutes or so and add some of that bactera supplement. Wait another 15 minutes or so for the tank to acclimate itself then go ahead and add your betta.
If he doesn't eat for a few days don't be alarmed. Bettas can live a full month without food (but don't ever not feed him for that long lol). When he's hungry he will eat- I would buy him a small ghost shrimp (typically only about 85 cents) and put it in the tank for live food. It's okay if he doesn't eat it right away, shrimps can do wonders for your tank. Also, maybe try other foods with him, freeze dried brine shrimp, freeze dried blood worms, frozen blood worms and different types of pellets. Give him some yummy goodness for a little while so he thinks that this new home of his is better, so he'll be happier.
I hope this helps. :)