Transcription companies not to work for

I emailed the company inquiring whether they needed transcribers. They contacted me and asked me to send a sample of my work, which I did and was accepted. Then more work was sent and I completed it but would not continue with the work unless a deposit was made. Then when the deposit was received I carried on with the other half of the work, I sent it in on time and almost two months later I am STILL waiting for the other half of my payment that is due to me. They make a lot of promises regarding payment; and then you wait for months for the balance to be settled.