Is it permissible for the debtor to dispose of his money extravagantly before repaying the debt, and what can the creditor do in this situation?

The uncle's delay in repaying his brother's debt, despite his ability to do so and his spending on luxuries, is considered an unlawful injustice and negligence. Scholars have stipulated the permissibility of punishing a debtor who is able to pay by withholding excess food from him, let alone excessive spending on luxuries, because the Prophet, peace and blessings be upon him, said: "The delay (in payment) of a rich person is an injustice." If the father will not sue his brother, and mediation has failed, then let him be patient and seek reward from Allah, especially if the uncle has become insolvent, for giving respite to the insolvent and waiving the debt for him carries a great reward.