You could make complain to our company if there is unhappy thing happen during the business.You could do that with these methods:
1. Please send email to our email box or call us to make complain: 
 Email: info@manypowers.com           Telephone: +86-755-8251-3067

2.Make complain to www.diytrade.com.  Because we are the chargeable member of diytrade company(see the link: http://www.diytrade.com/china/4/manufacturers/643887/bizverify.html ) so that once you need any help, you could contact them.      http://www.diytrade.com/china/4/doc/contactUs/Contact_Us.html  

3.Ask your country embassy in China for help.

USA: http://beijing.usembassy-china.org.cn/ 
France: http://www.ambafrance-cn.org/spip.php?page=sommaire&lang=fr 
Germany: http://www.peking.diplo.de/Vertretung/peking/de/Startseite.html 
Italy: http://it.chineseembassy.org/ita/ 
Spain: http://www.embajadachina.es/esp/