Maybe, You should contact other popular platforms that provide tracking volume of the exchanges and are making the ranking list among them.
For example, Coingeco is a popular one, as well as coinwatch.com.
But the fact that they will continue listing and providing trading and IEO services is more urgent and frustrating.
In this way, You could not restrict users from trading on this exchange, so IMO the other steps should be done in a legal matter.
legally speaking it could very difficult because they allegedly are from Mongolia and had some kind of company in UK, only those who were tied to this UK company could be legally responsible if they have not left the continent yet.
Putting pressure on CMC is a good idea, this way we at least will see if they care enough to act on this matter.