Not Contacting the Benefactor Turned Out to Be a Promise

He scored 697 points in the exam and was admitted to the medical doctorate class of a prestigious school. The whole Internet was praising him as "a noble son from a poor family". But he backhandedly deleted the benefactor who had supported him for twelve years. The curses were overwhelming, but he remained silent. Until a letter reveals the truth - there was a forgotten agreement between them. Goodwill is never a one-sided gift, but is passed down from generation to generation.