My roommate is so immature

Be
we get along but there are a lot of shortcomings. 
-She owes me $80 for the internet bill. 
-this is the sink. She won't do dishes and I want to wash a cookie sheet and the sink is full. 
When I ask her to do it she says no. She's making my pans rusty by keeping them filled with water because "stainless steel doesn't rust"! 
-She blamed me for leaving the door unlocked. She leaves out the front door, I leave out the back. She said I should lock everything when I leave because "she shouldn't waste her time locking doors when I will." I told her that I spend the extra second locking when I leave so that she doesn't worry and she flipped out that it's "not so fucking hard to do"
-She has 3 days worth of food packaging on the counter because since she doesn't want to do dishes all she'll eat is cup noodles.