Buying things piecemeal. This is also doubles as an answer to "why it's financially unwise to be poor." We buy shampoo, conditioner, and sometimes even soap in single-use sachets. Of course, it is more economical to buy in larger quantities, because you can control your portion sizes and whatnot. But when that bottle of shampoo costs the equivalent of the day's meals (two, maybe three), then the reasoning becomes understandable. A lot of stuff are hence available here in "single-use" sachets or packets.
A lot of these things have overlap with "travel-size" stuff that are actually quite logical when you're traveling, but for a lot of us here, it's what we buy week in, week out.
I have never been close to rich, but never truly poor either. 20 years ago my friend was in a credit card debt spiral of fees. I didn't get it so she explained how the fees for not paying back the credit card prevented her from paying back her credit card and she never had money because it cost money to not have money.
"So like.. what kind of figure are we talking about? What would you need to not have to pay one month's fees? And if I loan you this amount you'll be out of the debt spiral? It will fix this being charged fees so you keep having to pay fees bullshit?"
If you know the Terry Pratchett's Boots thing it was like loaning her enough for one good pair of boots and solving so many financial problems. Even something like that I would never have understood without it being explained.
This is painfully true here as well. Worse, it's not just credit cards. There are payday loans here that, while you can take out a loan without much hassle, you and your loved ones will be hounded by their agents if you even delay a single payment.
And then there's these loan sharks whose main shtick is to provide loans with 20% interest (so-called 5/6--you loan 5 bucks, you pay 6 bucks). It's kinda crazy to imagine that these loan sharks are the most humane one of the bunch, but with these loansharks, you can at least reason with them.
Those payday loans are technically in the clear, legally, via plausible deniability. Those who call and harass aren't supposed to be from the payday loan company, they're independent contractors. And since they target those who are strapped for cash, I doubt they've got any resources to file cases against the companies. The government? Maybe once in a blue moon when it's politically advantageous for them to make a show of possibly doing something about it. Otherwise, they've got other priorities.
The loansharks are like a cottage industry here, and they are kinda small businesses in themselves--just without the paperwork. No paper trail other than a simple notebook where the loans and repayments are recorded. Those who resort to them for loans often have no choice, and won't complain to the police about it even if it were indeed illegal. And the police? They've got other more lucrative business important things to take care of.