And I have just taken it back! It was in a box, so I couldn't see it. The box said "folds up for easy storage" so I assumed it was folded like that inside the box (which was fairly large anyway).
It turned out that it had to be assembled, and then, even when folded, it would be twice as big as the box. Also, once assembled, it could NOT be dismantled again for storage. So it was too big for me to store when not in use.
I took it back, had the £40 refund in cash, no forms to fill in (not even to say I'd had the money) and they didn't even look inside the box.
If I was dishonest, I could have kept the sack truck and taken back a few bricks inside the box lol.