my sister is an impossible person?

in thanksgiving i went to get out some noodles for mac n cheese and bread or stuffing. i got the noodles but forgot the bread car. she came in my room and yelled at me for not getting the bread, i told her i got it, she told me she didnt see it in the kitchen. i tried to tell her i forgot it in the car but she left the room before i could finish my sentence. i have admitted to things i dont do in the past to make things easier for me so my mother believed her and i wasnt able to eat thanksgiving dinner. every time i try to tell her its in my car she wont listen to me and she took my keys away so i cant even get it to prove my point to her. what should i
do? i do not want to keep on getting punished for something i didnt do. today she took my laptop and i have a paper due on monday.