Ah, I see now whats happened, This is actually Gypwall not Gypliner you've got hold of, no matter we can make this work if there's no way of exchanging it.
The system relies on both top and bottom channels being fixed, plum to each other, to soffit and floor respectively, the c channel, or studs, along with noggin channel, are self supporting.
So if you want to carry on with this? can you tell me which channel, stud you have (Gyproc nos. actual sizes and thicknesses etc. and photos if poss) and advise whether you can order the noggin channels...pinenot