Where to get plain high-waisted jeans?

Off-topic, but does anyone happen to know where I can buy a pair of plain high-waisted denim jeans, women's size 10?  You know, it is nice sometimes to have things the way you're used to having them, especially something you'll be spending as much time with as your trousers.  I've looked all over the place.  Everything is these wretched "Sits just below the waist" now, which means doesn't sit there but falls down.

I used to always get them mail order from M&S, but they've gone over to selling nearly all low-waisted jeans, only a few high-waisted styles and those are always odd in some way.  I couldn't get any last year either and my remaining pairs of jeans are getting to the point of being too tatty even to pass it off as a fashion statement!

I'm looking for:

* High-waisted, meaning a "waist" that is actually on the waist rather than below it.

* Straight rather than skinny (I'd never dare sit down!), and full-length not "Capri" or anything like that, which where I live I think would just be regarded as a good joke!

* Preferably pure cotton.  A few percent elastane or what not doesn't matter, but I'd rather not have polycotton, it's so much sweatier.

Any info much appreciated.