I know that you think you've been tough on her thus far, but if she's going to be back under your roof for ANY amount of time, you WILL have to get even tougher.
First, NEVER give her the option of leaving. When she comes to your house, that is per court order and CANNOT be changed under ANY circumstances. She doesn't make the rules, you and your DH do, along with the CO that was agreed to in writing by her bio-parents. Mom's rules don't apply to your house.
Second, before she is even allowed to get to the point of blowing up, remind her firmly that you may not be her mother, BUT she IS in YOUR house and as long as she is there, she WILL follow the rules....just like everyone else does.
Third, as for the phone, disconnect her if she's been reminded that her time is up. It's that simple. I'd do it to my own child in a heartbeat if that's what it took.
Then if she wants to throw a tantrum, clear a room for her, if at all possible. Put a mattress on the floor and ONLY give her the basics, absolutely NO privileges. Tell her that as soon as she starts acting like a responsible family member, she can earn her privileges back.
She will hate you even more. She will even try to refuse to come. But that's where you need to remind her again that it is NOT her choice. Per CO she is required to spend time with her dad as the CO states. Giving her choices of this magnitude is not appropriate for a child.
To tell you the truth, it sounds like she's going thru a major hormonal upheaval. (And reminds me of why I only wanted boys, LOL!) It will get worse before it gets better. But you CANNOT allow her to dictate what happens under your roof. Most importantly, both you and your DH MUST present a united front. Make sure you have it worked out ahead of time exactly what the repercussions will be for specific behaviors and stick to it. Your DH must stand behind you and demand that his DD give you the same respect she should give any adult. This united front is VERY crucial, because teenagers have a unique knack of finding the chinks in the armor and weaseling their way thru the holes. If they see any wavering on either you or your DH's part, they will exploit it if at all possible. Am there, doing that........