The 12 year old in a sweatshop in Bangladesh might be supporting a family and may otherwise have to resort to a lower income, starvation, or death without the opportunity Walmart offers.
That's the thing though. It is extremely unlikely that they are being "MADE" to work. Slavery is essentially outlawed. If you don't provide these people with better, higher paying alternative jobs, then there will be NO JOBS if you ban these.