Can an inmate be held in jail if the witness failed to testify?

My child father is being held in jail facing high felony charges such as robbery battery with weapon contiment etc. He is an innocent man. We know that this is a mistaken identity situation but he have been locked up for a month. Witness say he did it but its a girl who doesn't like my family because of this he has missed his only child first birthday. I have been contacting his public defender but no response. He have a clean record what should we do. We don't live out here so I'm stuck here until he is released.