I am a resident of California and I bought coupons from a person in New York.
When he sold me those coupons , some of the coupons were not accepted by the store and the person promised me to refund the amount if I send them back.
He sent me a prepaid shipping label and I sent back the coupons.
Now after receiving the coupons he refuses to give the money back stating that coupons are original and not duplicate.
How can I get my money back?
I do have it in an email where he is ready to send me the refund but now he is opposing it.
Kindly Help.

How much money are we talking about?

About $60...

... Now after receiving the coupons he refuses to give the money back stating that coupons are original and not duplicate.
How can I get my money back?

Why does he want duplicate coupons instead of the originals?

If you mean that he is refusing to pay because what you sent him are copies, send him the originals, duh.

The coupons sent back to him are original coupons. I have not photocopied or sent him anything else, I have sent whatever he sent to me.

He is stating "If they are copy of original, I will refund you. However these are original coupons, not copy of original. I can't refund you ".

He is simply refusing to refund.

So he is saying that what he sent you was the original and that is what you paid for. When he asked you to send them back, he thought that maybe he had sent you copies and that is why the stores wouldn't take them?. But since they are originals, he isn't willing to do anything about it, right?

Yes odinn7 what you stated is absolutely correct.
"They are originals, he isn't willing to do anything about it".

He didn't warranty that the store would accept them. So he has not breached the contract. You are out of luck.

Here is my communication to him :
I wrote :
The reason I ask is that your XXXXXX coupons are not being accepted in AAAAAAA and BBBBBBB... they are saying that the XXXXXX coupons are not original.
Will you accept these back... I have NN remaining .

He then wrote :
2012-11-19
"Yes, I can. Do you want to exchange to new XXXXXX coupons or just the refund? Let me know, I will email you prepaid shipping label. Thanks!"

He also wrote
2012-11-20
"$60 I will refund you as soon as I receive NN coupons."

But you said they weren't accepted because they were not originals so he took them back under that assumption. They turned out to be real as far as you or he knows.

Unfortunately, I think you are going to lose out here and just learn an expensive lesson from this.

The store mentioned that they are not originals as they coupons I was about to redeem had the same information on them. I was redeeming 2 coupons and they had the same serial number ,address etc etc...
He did send me an email saying that " I gurrantee coupons work. If not work, I will email you return shipping label, and I will refund you unredeemed coupons"

It is called being cheated, how much were the coupons,

Were some coupons used and worked correctly ? And with that many if not most coupons have the same "numbers" from news paper coupons, and most booklets that are sold do not have individual numbers for each coupon.

At the store, was this a high dollar item ? What type of store ?

In the end, you can try to sue them, but I doubt that you will ever get your money.

Yes, it was a high dollar item, up to $50.
It was a baby store...
Some coupons worked and some did not...

When I tried to reedem the coupon, the store showed print out from the manufacturer stating that it is a counterfeit coupon with the image.

Ok, 50 dollar, ( not really high value but I am sure it is to you)
high value would be a 2000 or perhaps more item like TV's or large dollar items

But it is still your money.

You can sue, do it in small claims court, he will not show up most likely, and you will win,
But he will not pay, and there is little you can do except win the judgement.
If this was a corporation you sue, most likely after 50 or so law suits, they go out of business and start up under new name, This is common.

But they should either refund the money or send the coupons back to you, since some where working. By not sending them back to you, you should win the law suit

I question two things -jurisdiction (which will be an argument in itself, particularly in Small Claims Court) and whether the OP has clean hands. I've seen these offers (coupons for sale) on eBay, later pulled for violating eBay "standards."