Yeah, mine got stuck at the triangle bit too. Sounds exactly like the same thing that happened to mine.

If you want to try it yourself, get another set of hands to help you. Take out the door trim and you will see that the vertical rails have probably gone askew and will not be sitting paralle to the window. If you just put it back into the rails it will probably happen again. Look down the bottom at the thingamybobys that is holding the window up and controls it going up and down- a part of this has probably unclipped somewhere and may be prone to pushing the glass up on an angle (mine was manky too I think).

You can take it to windscreen place, but from experience it didn't help as my friends fixed it and I wasted $100.