You, yourself, have to exercise due diligence. You should have followed up to make sure that the home was refinanced, and could have taken your ex- back to court had you discovered that it had not been refinanced by the agreed deadline.
How do you know that your father forged your signature?Quoting ollie
If the matter is reported to the police, they will investigate the allegations to determine what evidence is available of criminal conduct and, if the evidence warrants it, make a referral of the case to the prosecutor's office.

