I suggest you look for proper channel dealing with this as the amount is big. Get preliminary advice from lawyers. They should be able to advice based on whatever papers that you may have. Such as contracts, receipts, agreements and so on.

Make sure everything are well documented and you should be able to sue them. Also, notify the department that handles MLMs in Malaysia. I forgot the name of the department. It should be a company under ministry of finance.

Goodluck and make those leechers pay.