Any 'QUALITY' organisation would refund any money due. That is a matter of fact. Give Management the opportunity to reply to this allegation. Otherwise the customers need to organise a 'Group Action', and inform the Regulator to decide whether the ATO approvals should be withdrawn.
Aviation, in common with other service providers, have those who are reputable, and those at the other end of the spectrum who are not fit for purpose.
Do not part with your hard earned money without conducting due diligence.
If it sounds too good, it is probably is a scam. Avoid gullibility. A good test if you enter aviation.