We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Liquorice"
saying something like:

You know why they want that and instruction books etc etc don't you? It's
so they can take your return, bung it through the shrink wrap machine in
the back of the store, and sell it "as new" again.

In some cases, that's the way it works. B&Q supplied some PIR carriage
lamps, with a 50% failure rate - on looking at the boxes, it was obvious
they'd been returns. I hadn't bought them, was just fitting them.

So if taking something back to a store like that write in the instructions
that the goods have been returned on such and such a date and why. Or
scrawl on the box, in thick black marker, "Return to XXX, splinge wurdle
broken" OWTTE.

I (luckily) have space to play this game and always keep the boxes. I
scrawl on them in big FO indelible letters, the date of purchase and how
much warranty. I've not had one refused yet.