let your grandparents knows and your aunt and let them deal with it
I'm sorry to say, I guess you cant do anything about it then,
make sure you hide your stuff in a good places next time
get one of the trunk type storage boxes with a latch that you can put a strong lock on it. keep that in your room and put your most valuables in there. it can double up as a coffee table too. i used that in my early college days and i still have it to keep stuff.
first calm down , dont let something bother you that wont bother you anymore in ten years. <br />
So maybe go through your uncles room? and you should get a chest you can lock so you can put important things like laptop bags and purses in so it wont happen again