Whenever I have had a conflict with a roommate, I have always found that a calm discussion at a neutral time was the best way to resolve the situation. I once had a situation with a roommate who would always leave the bathroom light on. There was a faulty screen in the bathroom window and overnight the room would fill up with bugs who were attracted to the light. She went to bed a lot earlier than me and the bugs would escape again by morning, so she never saw the problem, but I did. I tried leaving notes, but it didn't get through. Finally, I found a time when neither of us was busy or in a hurry, and calmly explained the situation to her. I explained how much it bothered me to go into the bathroom at night with moths everywhere. It turned out, she didn't really understand how many bugs were coming in and she was also having a problem because there was no light in the hallway and she was having trouble coming up the stairs at night after walking her dog. Once she understood how bad the bug situation was, we were able to find a solution together; she started only turning on the bathroom light when she was headed out for a walk and turning it off again on her way back in, so it wasn't on all night.
So, you can make one more hail-mary attempt at reasoning with this person. Find a time to sit down with her at a neutral time (not when you've just been woken up by her and tensions are high) and try to calmly explain the seriousness of the situation; that you can't sleep due to her activities at night and it is affecting your work/life/etc. Come armed with solutions: ask her if she would be willing to make some reasonable accommodations, like wearing headphones when she is watching videos and closing her door when she wants to talk on the phone. These are very small requests and any reasonable person would grant them, but she doesn't sound like a reasonable person; if a visit from the police did not alert her to the seriousness of the situation, I don't believe there is any way you could phrase your request that would get through to her.
Have you considered a white noise app for your phone? This should drown out a lot of the outside noise without disturbing your sleep or anyone else in the apartment. You can set it to time out before your alarm goes off so it doesn't interfere with your morning. A friend of mine uses one because her husband works late nights and was always waking her up on his way in, and it has worked very well for her. I think this will be the best solution until you can change your living situation. Good luck!