Thanks for choosing Apple.
Hello again,
This is just a quick follow-up to your previous request. I wanted to ensure that your iTunes Store issue has been taken care of. I am looking forward to your reply so that I can be certain your request has been fully resolved.
Hi Nattapoom,
Phong, here from iTunes Store Customer Support. I can see from your email, that you mistakingly typed in the wrong email address to use the application you just recently purchased. I’m sorry to hear that. I understand that you would want to be able to use the application. I know that I would want to be able to use the application as well. I’m happy to help you with this matter. 
I’ve reviewed your case and am issuing you a full refund for the unintentional purchase. Within ten business days, 0.99 USD should be posted to the payment method used to make the purchase.
For your information, the iTunes Store provides a warning message that asks if you’re sure you want to buy an item. This warning can be turned off. If you’d like to make sure that this warning is on, you can reset the warnings by following the steps in this article:
https://support.apple.com/en-us/HT201620
You can also set restrictions on your iPhone, iPad, or iPod touch that will prevent purchasing. See this page to learn how:
https://support.apple.com/en-us/HT204396
Thank you for choosing the iTunes Store. Please feel free to reply to this email if you have any further questions or concerns. I am happy to help, and want to ensure that your needs are met. Enjoy your day! 
With best regards,
Phong
iTunes Store Customer Support
http://www.apple.com/support/itunes/ww