Daughter ASKED to be put back into care

One year ago my wife and I meet a beautiful, smart, and outgoing 14yr girl. We fell in love with her. We knew about her issues with attaching, boys, social media and others. However we wanted the best for her and wanted her to be our daughter. Over the past year, it was trying. After the honeymoon period things went down hill. It was harder and harder to get our daughter in engage with us, spending most of her time watching tv. It was hard on us and hard on our marriage. My wife and I increasing lost patients with each other often arguing about what to do and how to handle our daughter. There were times that our daughter left the house for a weekend due to arguing and needing space. During some of the arguing my wife said somethings in anger that she apologized for after and seeked out therapy to deal with some of her personal issues. However after the last fight, my daughter made the call to her worker and asked to be put into a foster home. My wife and I have worked hard on resolving our issues and want to adopt our daughter. However she is very angry and will not even take our phone calls at the foster home. It has a few weeks and she is not given an inch. We have spoken to her friends and all she is saying is that she is done. My wife and I are very hurt and devastated that she might not be coming back. To us she was our daughter with no questions asked. Has anyone been in this situation or something similar? We can use any advice. Anyone have a time frame of when this pass?