Man, what an experience. It's like a claustrophobe's worst nightmare. I think the middleclass snob's phrase is 'chav-tastic'.
Still I did manage to stumble across the luggage department, or 'landing' as I'd tend to call it. Choice of luggage was limited to those huge monolith-like oblong bags with the extendable handle on the top and the two wheels on the bottom. You know, the sort of thing that encourages people to fill them to stupid proportions in the mistaken belief that there's no such thing as 'stairs', and then yank them across your path so you go flying.
Anyway, these Dunlop bags were cheap and available in either black for boys or candyfloss pink for the girls. I went to the Kathmandu store in the end and got a rucksack with a 40% discount. Result.