Your apostilled degree, police check and TEFL certificate are submitted for the work permit — and the contract states they become the school's property and will not be returned. Losing these is far worse than losing a month's pay: replacing them can take months and blocks your next job.
Search the contract for wording about 'originals'. If it says they are retained, do not sign — originals must be returned after the permit is issued.
A direct contract quote — not a paraphrase.
Poster quit after 14 days; documents never came back.