What should I do if the father of my child refuses to give her back after seeing her that day?

If you have an order giving you custody and visitation to father, you have the right to enforce that order.That order may or may not state when and for how long the visitation is to take place. If it does, you have the right to file what is called a "show cause" against him for failure to obey the court order. This is almost the equivalent of a criminal charge, but not quite. But it brings him before the court and the court will ask him to explain himself. If he cannot there will be consequences. Failure to obey a court order is called contempt of court and it is taken pretty seriously in some jurisdictions. Now, if you do not have a court order giving you custody and setting out a visitation schedule, there is very little you can do. And my advice would be to file a petition for custody and visitation as soon as possible. And to seek the assistance of an attorney in doing so.