employer does not allow rest day and have my own hand phone

I am a DH here in malaysia. My employer is quite nice but they do not abide with the contract we both agreed and signed. First, my salary should be 400usd. But now they are paying me 1200 ringgit Only (suppose to be 1400+ ringgit when you convert the 400usd to ringgit) . Second, is my rest day. They only allow me to have rest day twice a month, its fine with me but they are not paying the other 2 rest days that are suppose to be an Overtime according to my contract. Third, is my passport. The immigration here is very strict and you should bring your passport or ikard when you go out. But my employer does not give me my passport or ikard or any copy that i can present that i am a legal worker to any immigration or police should i be question when i go out. And lasty, my salary. The agenxy asked me to sign a 10month agreement that i should save 500rm of my salary to my own account for 10months. But there are times that I need to send more to my family and they wont allow me. But since its my own salary, i should have the right the control it right? What will i do with the above written problems with my employer and agency? Need fast advise please.