Unionizing wasn't such a contentious issue when employers were working their employees to death and paying them in credit to be used at the company store.
That is incorrect. Unionizing was strongly opposed throughout the industrial revolution. Look up Pinkerton's efforts, the Haymarket incident, many others.
Yeah, of course the bosses didn't want it. It hurt them and their profits. But back then, the people wanted it. The difference between then and now is, now when the bosses say "you don't want a union", the workers actually believe them.
Which they're obviously not now, so I'm not sure what your point is.
Isn't this essentially how Wal Mart operates in the US today?
When I was in college I worked at a regional Wal Mart competitor where I made minimum wage (not enough to live on) but got a nice discount if I bought from the store itself (which made my wages about enough to live on). It's as close to the old "company store" as they can legally get away with these days.