Having to modify parts to fit the product!!!

I recently purchased the Stiletto Studio Chair, #91-1106115 and upon assembly, the threaded portion of the knob that is designed to adjust the backrest support bar is approximately 1/2″ too long and the back support.

Because of this, I have to go to the hardware store to pick up a nut to fit the threading properly, attach the nut to the “bolt” portion of the knob, cut the excess of with a Dremel tool, remove the nut so that the threads are clean enough to re-attach the knob to the backrest support bar.
My question for you and your team is this,
Do you assemble these products that you distribute, or do you just take it for your vendors word that these products are in working order and are turly ready for assembly?
The chair I purchased was the only one on the shelf at the store I had purchased, but they did have one on display, but that was on an elevated shelf, out of reach for me to examine.
If this issue is a one time thing, I can personally let it go. Mainly because I have done this similar type of fabrication in the past, but not after making a purchase of a brand new item.
I would really be upset if I was not in a position either by skill or knowledge to remedy this situation.
Please rememdy this for any and all other possible customers.

“C. [1] Backrest
Support Bar
Note: Part [J] is
attached to part [C]”

“J. [1] Knob
Note: This knob is
attached to Part [C]”


Click to access 91-1106-stiletto-without-arm.pdf