How is repetition used within the story about Kunicki and for what purpose?

When Kunicki's wife and son vanish during the family's island vacation, Kunicki is nearly driven to distraction. While he is conducting an exhaustive search for his wife and son, the locals keep telling him versions of the same message. They keep repeating that the island is not very big, as if this is useful information for a man whose wife and small child have vanished. The repetition therefore underscores Kunicki's frustration and feelings of helplessness at the scope of the situation.