How can a young man who broke a girl's heart and played with her feelings absolve himself of his sin merely by repenting, and does his obligation towards her fall away with that, and what is the way to restore this girl's right?

A woman must avoid everything that leads her to temptation. If she is lenient with someone who toys with her emotions, she bears the burden of that sin. As for a man who promises to marry her and then breaks his promise without a valid excuse, he is sinful according to those who hold that fulfilling promises is obligatory. The questioner erred by corresponding with this man and informing him of her feelings. The supplication of the oppressed against the oppressor is limited to the extent of the injustice.