I don't believe IDAX did a scam because in recent months they have just become a member of the coinmarketcap .
I also don't know the full details about this problem, just wait for the clarification from IDAX.

by the way, here is the proof their membership.
https://medium.com/@to.liuwen/idax-has-become-a-member-of-coinmarketcap-transparency-data-alliance-4dc027216f7d