Who should I sue? The site has no official representatives and a registered company.
Official representative: Ivona Zlatova, CEO
I can find past registrations for Red Velvet Investments in the Bahamas and Belize
I also found this
review but I don't how accurate the information is:
Livecoin.net is a company officially registered in our country, which is subject to the laws of the Russian Federation. Thus, in its work, the organization adheres to the following principles: ensuring the security of the cryptocurrency trade process, the confidentiality and security of users' personal information, anti-money laundering and fraud support.
Some things you just can't find on the internet. If I were you and I was really serious about this, I would hire a lawyer or some sort of legal aid to help you research the matter. Perhaps you could get a free consultation at a law firm.