Can CPS refuse to do a reunification, even if I have SUCCESSFULLY completed all services.

Quick summary: No drugs, no alcohol, never tested dirty, stable housing, employment, and transportation. 3 years ago my daughter was removed from my care. CPS stated they believed it was her dad who injured her (whom resided in the household). They could never pin down exactly if it was him, a babysitter, or a family member who watched her while I was at work. So, no charges we're ever brought forth. The GAL, CPS, investigators all stated on and off the record that they didn't believe that I injured my daughter directly. Fast forward three years and as many caseworkers. I have since had another child, whom the court left in my care, since I have completed and benefited from the services they offered me. However, they still will not return my oldest child to my care. Instead of reunification, they are seeking guardianship. The issue I have with this is, I've already completed everything. There is nothing for me to do to. It doesn't make sense that this should be dragged out any longer.