Sadly, there is not much you can do about the problem in general.
Trademark, copyright etc... its very difficult to have those respected in other countries. Sure there are treaties and such, but to enforce them is very very costly. I'd be surprised if Rev, which is one of the top kite producer, would have even close to that kind of cash lying around to sue international.
Basically, when you start making goods that are much more expensive than the material it takes to build it, you should know that if you are successful eventually you will be copied by China. You just have to take it into account. You can't hide it, you can be in denial mode however you want, the problem is not going to go away.
If your business plan took that into account in the first place, then you have nothing to worry about.
If you never took that into account and its killing your business... well... you probably should of given it some thought before dumping all that cash to start up your business, its not 100% the fault of Tan Bo
Its like shoplifting. Its illegal, and it will never stop, but stores take it into account and they calculate it in their business plan.
I'm not saying that its right, I'm just saying that there is not much you can do about it, except analyze it and try to figure out if your company can survive even though it exists (and will continue to exist). If you did a good job about it, you will manage.
On the other hand, I do not even go into the debate of what happens if you do not protect (patent) your inventions correctly and someone legally copies your kite [or whatever you made]. We can always debate that its immoral. But its clearly not illegal, they should be allowed to sell it.