I suppose mistreating them depends on your point of view and how seriously you want to take the narrative. Wonka discovered them when he traveled to Loompa Land. In Loompa Land, the Oompa-Loompas were in constant danger from many different predators. Wonka offered them jobs. They are paid in cocoa beans, which are their favorite food, and were in short supply on the island. Before publication, they were named ‘Whipple-Scrumpets’. They are as mischievous as Wonka. As each child exits, they sing a song about the child’s bad deeds to serve as a moral lesson. In the text, Oompa-Loompas insist on wearing the same clothing that they wore in Loompa Land. They are described as small people with long hair.