what should i do, my passport is in the agency and we can't contact the agency now ?

i come here im china and my friend give me work to a Chinese family and bcoz my visa is about to expired they say they need to hold my passport to be renewed, for how many months working to them they deducted my salary everymonth and get a big money to me. my boss said they going to live the house and i should find another job and when i am getting my passport with visa to them they say i go and contact the agency,when i contact the agency they said i need to pay more money but i don't have money left because my boss didn't give me money. and from then i wasn't able to contact the agency and they transfer another place for their office and i don't know what to do now.i want to go home Philippines. what should i do?