Gross irritation

On the left, what I thought I was buying. On the right, what I actually got. Along with a minute drawing, one of those sets of instructions without words. One supposes that the tiny smudge might be a bolt, that the faint dotted line indicates a hole to put it through, and that somewhere in the bag of bits there might be a nut to fit the bolt. And so on, and so forth. That sound of rumbling you may be hearing in the distance is me grinding my teeth. Thanks for nothing, Screwfix.