It seems to me that this is the only chance to get clients' money back. As far as I know, allegations of crime have been filed in at least 7 countries (we are talking about those clients with whom we personally communicated). Moreover, in some of them, law enforcement officers at least verbally showed interest in this case.
Therefore, if you want to submit a similar application on your own behalf, I can help you draw up an approximate example of such an application.