I don't think the consultant hired was licensed so there was form filled nor signed. It definitely is an unfortunate situation that has happened . Also to note is there are few licensed consultant operating overseas, so it is hard to find a reliable unlicensed consultant.
That is unlikely to happen, as stated in the notes according to officer he/she doesn't see the IMM5476 and hence it is straightforward case to the officer. And most likely this consultant is not licensed so there was no mention of his license number nor his name so this consultant can't be legally held responsible for this mess and hiring an immigration lawyer is of no use because there isn't any evidence to bring him to justice.