It is unlawful for a principal to discriminate against a contract worker—
(a) in the terms or conditions on which the principal allows the contract worker to work; or
(b) by not allowing the contract worker to work or continue to work; or
(c) by denying the contract worker access, or limiting the contract worker's access, to any benefit associated with the relevant work; or
(d) by subjecting the contract worker to any other detriment.