Hi Suthee Thairat,
Thanks for sending the proof of purchase for this product:
Product: iPhone 5c
Serial number: F2LLJ3AKFLFW
After reviewing the provided documentation, we unlocked the product.
If you need help, use Contact Apple Support to start your support request online and get connected to an expert:
Contact Apple Support
http://www.apple.com/support/contact
For more information on Find My iPhone Activation Lock in iOS 7, see this article:
iCloud: Find My iPhone Activation Lock in iOS 7
http://support.apple.com/kb/HT5818
Thanks for contacting AppleCare!
Bob Kim
AppleCare Account Security