Suito - missing part

[alexmj]

Hello,

An Elite Suito I received recently seems to be missing the nut which holds the freehub against the trainer. Without it, I cannot remove the 105 sprocket from the freehub, the combined sprocket and freehub slide around loosely while riding, and the spacer does not position itself correctly along the axle.

I've attached a picture of the part illustrated in the instruction manual, and the location that the nut should thread on to.

Is it possible to receive a replacement? Or, what is this part called so I can find a replacement?

Thanks. I am looking forward to riding soon.