What is the theme in Vengeful Creditor by Chinua Achebe?

Class conflict is the main theme in the book. In "Vengeful Creditor" the interests of the middle class are pitted against those of both the rich and the poor. The Emenikes, with their civil service jobs, are certainly comfortable enough, although they are neither as wealthy as Mr. Emenike's friend Mike Ogudu, who owns a shipping line, nor as powerful as the Cabinet Ministers whom Mr. Emenike serves as a Permanent Secretary. Compared with the poor, however, who have barely enough to stay alive, the family is extremely well off. Because of the desperate poverty of the majority of the country's people, the Emenikes are easily able to exploit their unfortunate servants.