In some countries where the consumer law is protective enough you can basically get those USB sticks for free. You buy them and then use a linux tool[0] to prove that they are fake. It also allows you to fix the flash drive to report its size correctly. Using the evidence you claim a refund. In my experience the seller doesn’t usually bother with a return which will be at their cost. So then you’re left with the USB and your money.

This also incidentally has the effect of making their business less profitable, so arguably it’s your moral duty if you can do this at no cost to yourself.

It really depends on the platform and your country’s consumer laws. Some platforms force a return which makes this whole exercise not worth it.

[0] https://github.com/AltraMayor/f3