This is something that should be raised through your year rep who will raise it through the staff student committee - where it will be minuted and actioned.
The big question is, did the promotional materials etc state that there would be a placement year? Or were things phrased in such a way that there "may be"?
A big change to the curriculum like this would normally have to go through a process of restructuring. It doesn;t sound right to me that it could just be dropped, unless the way that it is built into the course allows that kind of flexibility.
So, as I say, as a matter of urgency raise this with your class rep and get the ball rolling.