screen time

as a quiet student that has been staying out of trouble for the past 2 years, i'm just........frustrated. I understand if i did something wrong to have my screen time limited but now i have it limited with no explanation as to why. As i was doing my school work, i went on my phone to look back at my notes that i had taken a picture of in class and before i knew it my screen time has reached it's limit and it would stay like that until 3 DAYS LATER. My sister has the parental controls on my phone but she was at work so i told my mom about it. She told my sister to never do that again unless there was a good reason. My sister claimed she never made any screen time adjustments so i was a bit confused. I'm not sure what to think of this honestly because this is the second time this has happened throughout this year. The fact that she still has parental controls on me is just telling me she thinks i can't change at all even when i put in a lot more effort to become better. I'll leave it at that