Yongnuousa.net only warranties items purchased on our site. For warranty service or other questions on items purchased elsewhere (amazon, eBay, b/h. adorama etc), you must contact that seller or contact Yongnuo directly.
Their email address is Service@hkyongnuo.com
If you have a question about an order that originated on www.yongnuousa.net, you can email us at firstname.lastname@example.org