3rd party app security and privacy violation

I'm new at communities and English is not my native language, sorry in advance.

I am deeply concerned about 3rd party app named "Chibi Bomber"s privacy and security measures. Their "admins" share username / passwords to third parties. They steal your account and delete all the in game items that you bought via in-app purchase.

So I contacted facebook page of the app, which by the way is described as the app support at app page. And they said "we can't give your stuff back etc. etc." And then something unexpected happened, somebody called my cellphone and addressed me with my name and surname. He said he got my personal info from the administrator who is in charge of facebook page.

They share my password, and they share my personal info to 3rd parties. I can not report a problem to game developer, because the contact address they specified is the facebook page. And they are the ones who shared my infos.

So, what can I do now? I'm going to begin legal actions against the application but it's effect may be limited because that companies hq is in China, which means it is not in jurisdiction of my country. I can not contact developer for obvious reasons. What should I do?