Legal rights as a mother?

I allowed my 14 year old to stay the week with her father, who has been absent most of her life, and now she doesnt want to come home! I have it under good authority she has been running around town doing whatever she pleases. She is wearing clothes that are unexeptable, and I know that her father has not been around the whole time. She is being cared for, if you can call it that, by her fathers girlfriend, of only about 6 months, so this woman really does not know my child. And the cops say I have no rights, because she is with her dad. Anyone have any advice on this for me?? I am in such distress, so blown away. I do not know what to do. A little more on the situation, since her father has been in her life the last 6 months or so, she failed her classes in school, and has been very disrespectul to everyone in our family, including me. Please help!!