You've just reminded me of something my dad once did to me 
My folks were really easygoing. But they drew their battle lines and you didn't cross them. We could get away with quite a lot, but we also knew that as soon as we crossed that line that was absolutely it. And punishment was always inventive in our house! I was never smacked. I don't even remember being threatened with it - ever.
I had a TV in my room as a teen. I could watch it, but only up until whatever time we'd agreed. Of course, I thought I was being really sly switching it on late at night and turning the volume down when I was about 13. This went on for weeks and naturally, I thought I was getting away with it. Until one day I came home, went up to my room, switched on the TV only to find it wasn't working. The reason, I here you ask? My dad had cut off the damn plug and then put the TV right back in its spot. I can remember like it was yesterday him coming into my room and asking me how my day was, like he hadn't just hacked my TV to pieces, and I just stood there looking between him and the now visible wires where the plug used to be, not knowing what to say. Because if I had questioned him about it, I'd end up either admitting that I'd broken the rules and that he was right for punishing me, OR I would have ended up lying to him about watching the TV which would have resulted in further punishment.
Lesson learned the hard way. My dad wouldn't have cared if that TV cost him a kidney. He still would have taken a mallet to it to prove a point. And because of that, because I knew down to my bones that nothing I owned was more valuable to my parents than my health and well-being was, absolutely nothing was safe if I acted out. My dad was the sort who, with regards to your texting at night issue, would have let it go a little while to see if I stopped. He would have given me the benefit of the doubt and a chance to listen to what he was asking, until he felt battle lines had been crossed. THEN I would have found my phone floating in the fish tank. And he wouldn't have cared how much the phone cost, because if I learned my lesson, to him, the loss was worth every penny.
He also removed my bedroom door once, after asking me nicely for months to stop slamming it every time I got in a strop. Took me ages to earn the damn thing back lol.
I think what you need to do is sit your DD down and have a little talk. Tell her that you lay down rules because you love her and want to take care of her. That you're good parents and not that hard on her, but that there are consequences to her taking advantage of your leniency. Pre-talk, you need to decide your course of action for rule breaking. You discuss this with her, come to an agreement, and by god do you stick to your guns if she takes the 
You don't need to smack her. Your daughter never needs to fear YOU. But as far as I'm concerned, a healthy fear of what you'll do to or with her things should she act up is a pretty neat option 
If the phone's an issue and causing behavioural problems, I'd be finding a creative way to take that phone...out of the picture.