How do i know if someone really did file an injunction against me?

My ex's mom claims that I owe her money for part of a family plan I shared with her son while I housed him for over a year ending last year. I had never actually talked to her about it and now he sends me an email saying that his mom has filed an injunction for 600 within two weeks, which I was told six months ago she only wanted 400(mind you this bill is for only 2 months so i dont know how it got so high). How do I know she really filed it and what will happen if I dont pay it?