I need my domain (atlasalan.fun) removed from that old account

To provide some additional context AeonFree are another company that use IFastNet for their infastructure. So the same Domain can’t be registered to both otherwise the name servers at IFastNet don’t know where to point the domain. They also seem to have a fairly active forum over there, so you should be able to get help if you’ve lost access to your AeonFree account