"I'd like to see them protected from extortionate credit rates, with a clear responsibility on the part of the retailers to explain with APR means long term "
Which is fine, although you have to accept that it will leave a lot of people, mostly the people you're trying to help, unable to get any credit at all. One person's extortion is another's risk premium, and there's no evidence that these sorts of places are actually making vast profits.
There's a social problem, though, and for those with a copy of Bruce's Nebraska to hand, the key track is Used Car. Generalising wildly, people with money buy second-hand cars, supermarket own-brands and clothes from charity shops, because they don't have to. People who actually have to do this reset it wildly. Some of this is purely practical: I can run old cars because I have the cash to repair them on hand, and if I absolutely had to I could go and buy another one; that means I can run an old car (current has ~100K miles, one previous one got taken to ~180K) and take the occasional knocks in exchange for not paying all that depreciation. We also have two cars, so the practical implications of one of them needing prolonged work are limited. If I hadn't got the money on hand, buying a cheap new car with a three year warranty and servicing pack on a high-interest loan sort-of makes sense: it's three years of getting to work for a roughly fixed outlay, plus perhaps a couple of front tyres.
The same goes for domestic appliances. If you have the money, you have two options: buy a sequence of dirt-cheap ones, and accept the fact you might need a washing machine pdq, or buy Miele with a ten-year guarantee and forget about it for a while. But for people with a fixed, small income, a new Hotpoint with a few years' warranty makes a certain amount of sense. It even applies to food: I can buy cheap own-label coffee, which is usually fine, but if on the odd occasion it's shit, no biggie. But that's where it's not actually about practicality: that's where I can choose to buy cheap stuff, without impacting on my self-worth, whereas for people who are forced to buy cheap stuff, it's rather different.