Is it permissible to publicly shame a person who has not returned the money he borrowed from his colleagues, by describing him as a "fraud and a thief" and publicly warning against him?

It is impermissible to mention a Muslim with what he dislikes, as that constitutes backbiting, unless he is a swindler and a thief who does not return rights, in which case it is permissible to warn against him. However, if he is in financial straits or his condition is unknown, it is not permissible to lie about him, but it is possible to inform of his condition if there is a need. If it is proven that he is wealthy but procrastinates, then his honor and punishment are permissible.