I'm truly sorry that you've lost your daughter, that must be hell.
I've read your post many times and I'm confused by some conflicting information that does make me wonder though if your daughter is in a safer place for the time being. You said that your partner is in jail mainly because of a VRO you took out on him.
This means that you're admitting you're still in a relationship with a man who is violent towards you and abusive to your daughter. Yes, witnessing violence is child abuse. Also, people don't go to jail just for having a VRO. People get them regularly. What did he actually do to get put there?
The people in charge here are DCP. Play by their rules. They want urine analysis for a reason. Give it to them, clean every time. Do exactly what they want, leave when they ask you. They're not going to have a meeting with a hysterical woman. Be calm and determined. Create a clean record with them so that when they go to court against you, you have a history of compliance. And respect yourself and your child better than to be in a relationship with someone who causes this much disharmony to your life.
I come to you as a grown woman who WAS a child taken into foster care due to DV. Growing up in a DV household is another kind of terrorism- home-bred terrorism. I first learned to pray when I was 9; when I thought I was listening to my mother getting murdered in the kitchen. When I got removed and placed, I missed my mother terribly don't get me wrong. But it gave me a safe place to recover and discover what being a normal child was like. Well, as normal as it could get. At 35, I still occasionally get night terrors where I'm taken back to my early childhood.
Be happy your daughter is safe and is recovering somewhere. And work on making that place with you again. This is a clear cause-and-effect situation.
DCP aren't the cause of this problem, they're the effect.
Work on the cause so you have the effect.