My room is an awful mess?

Okay, so I have 5 brothers and sisters. One went off to college so it was just me and my sister sharing a room. We recently moved houses, and there is one less room because my brother moved out. Well, my sister (who is 17, very rude, disrespectful, doesnt care about college but is going in the fall, and thinks shes sooooo awesome) got her own room and im sharing with my sister (whos 15 and im 13) which I was okay with. We have shared a room our whole lives. But, my brother came back recently from.college and is visiting for a while. He was gonna get his own room so my sister had to share with us! My mom put another bed in our room! (me and my sister use a bunk bed thankfully) . So here we are, crammed in this room. My 17 yr old sis leaves her crap (clothes, makeup) everywhere, ans my other sister is becoming just as unorganized. I try to ask them to tidy up and they r always like "i dont care". To top it off my mom TORE OUT PART OF THE CARPET and my mom never finishes what she starts , so we are stuck with a huge hole in the carpet when you walk in amd a disasterous room! I camt have friends over and its not a comfortable place anymore. What should I do? Thanks!