Purchased a over head shower unit and found on fit...

Purchased a over head shower unit and found on fitting it that the thread that goes through the ceiling was no where near long enough to get a locking nut and connector on !!
I was told by a member of staff we sell loads of these and that s how it is !! He suggested using a wall plate connector and building a frame in the loft to attach it to! I found their attitude very unhelpful as they seemed not to really care.

Beware !!