The theme of the play "Refund" by Fritz Karinthy is the value of education and the expectations that individuals have of the institutions and teachers that provide it. The play follows the character Wasserkopf, a former student of the school, as he demands a refund of his tuition fees because he believes that he received no value from his 18 years of education. The teachers and principal of the school are faced with the challenge of defending the value of their institution and the education they provided to Wasserkopf. Throughout the play, the characters engage in discussions about the purpose and value of education, as well as the responsibilities of both students and teachers in the learning process. Ultimately, the play suggests that education is a valuable and worthwhile investment, but that it requires effort and dedication from both the student and the teacher in order to be successful.