My daughter would do that too. We manage access using parental control software. We use Qustodio however I have seen other applications ( https://screentimelabs.com) that allow the child to earn time. Microsoft also has good parental controls that ask you (the parent) if your child can have extra time when they use up the day's allotment.

Those applications can take some of the burden off your shoulders of policing and enforcing rules. We have also found it diminishes tantrums since we are not the bad guys taking her electronics away.

We have made a little progress in that he has promised that once a week when he gets home he will wait an hour to use a screen. We also have an 1 1/2 hour a weekday of mandatory homework-btw that doesn't mean he necessarily has that much homework- it means that his grades have fallen (because of video time) and this is time spent either studying, doing homework or reading. He is also at away camp for 8 weeks where no screens are allowed. We also discussed after school activities and increasing the amount next year.

So, I don't have an answer for you and I am struggling with the same problem. I have a 15 year old boy who could sit in a room all day and not remember to do anything. I do have a safe I bought just to lock all his screens away-that worked until he found out the code and now I am using the car as well. I have talked to him about addiction and how it can impair life. He sees it, but at this point he is not willing to give them up. That being sad, it is like a food addiction because he uses a chromebook everyday in school and it is the only consistent motivation for him. I am kind of holding my breathe, because I feel like until he matures and is able to process the amount this affects him, I am limited in what I can do. I don't mean that I give him carte blanche to have them when he wants, but It is like any other addiction, he has to get to the point where he can use them as a tool, not as a crutch.

Phew that's a tough one. I don't know how extreme you're willing to go or if it's even a solution but if she keeps that up I would either get rid of the electronics all together or put them in a locked box that she can "earn" the right to them by doing chores or something. To lie to your face is a huge problem and shows she has no respect for your authority as a parents so maybe you need to get a little harsher. I'd be curious what other parents think though since each parenting style is different. Electronics are NOT a necessity, they are a privilege that she needs to earn.

Sounds like a typical teenager, we all did the same, however it's still unacceptable.
Does she understand why they were taken away? Advice: If so, explain when she can get her electronics back, make a token chart with a list of your wants from her. Completely deactivate both items in the meanwhile until she acts the way she should. Let her know that she needs to earn her items back, that's where the chart comes in..