Hello theyiqin, as we are not a copyright legal firm. We are unable to advise much. See below for our personal opinion. End day, it is better to check with a proper copyright lawyer.
Our suggestion is: You can do a copyscape search and show them that they have copied your content. You must give them reasonable time to take down the content. Should they refuse, you can do a who.is to check their server and inform their web hosting company about it.