my employer refuse to give my passport back

i got English teaching job in Shandong province last year august. Before then i had a business visa and the new job they had promise to change my M type to z type.The training school was new no students, location not good at all. the owner of the school told me that they'll be students, the guy is well connected with government officials so i trusted him. it was very unfortunate that we didn't got students actually they were only two students. he already changed my M type to z type but he did gave me a copy and refused to give the passport. am stranded because from august last year to this year February 2016, the owner haven't paid me a single cent, he just provide house and meal. he told me that he spent a lot of money for my working Z type around 38000rmb so i have to work for the fee. i never heard of that before. now my big question is, will the guy agree to give me passport once he recovers his fee?.I think by the end of feb 2016 he will have recovered his fee based on the fact that he deduct from the basic salary we agreed. no signed contract.i f he refuses what am i supposed to do?