What is the recompense for a man who promised a woman marriage then exploited her to fulfill his desires and broke her heart, and will Allah take revenge on her behalf for his injustice towards her?

It is not permissible for a man to take a woman as a secret girlfriend to fulfill his desires under the pretext of engagement. The relationship between two non-mahram individuals is not permissible except after a valid Islamic marriage contract. Direct contact between them without the guardian's knowledge and based on false promises leads to problems and corruption. Both the man and the woman must sincerely repent and abstain from forbidden acts. A woman should not grieve over a man who possesses the characteristics of hypocrites, such as lying, treachery, and breaking promises, for the Prophet, peace and blessings be upon him, said: "There are four characteristics, whoever possesses them is a pure hypocrite; and whoever possesses one of them, possesses a characteristic of hypocrisy until he abandons it: when entrusted, he betrays; when he speaks, he lies; when he makes a covenant, he is treacherous; and when he disputes, he acts immorally." A man may leave a woman due to her lack of commitment to religion and morals, and there is no blame upon him for that.