Is the failure to mention one's beneficence to others, out of fear of embarrassing them, coupled with complaints about their ill-treatment, considered a disease of the heart, and what is its remedy?

A Muslim should mention and spread the good deeds of his Muslim brother, encourage him, thank him for what he has offered, and conceal his mistakes. Therefore, a Muslim woman should thank the sister who helped her, mention her good deeds, and conceal her mistakes, because the Prophet, peace and blessings be upon him, said: "He who does not thank the people does not thank Allah." This means that Allah does not accept the gratitude of a servant if he does not thank people. This ailment must be treated by rewarding kindness, or supplicating for the one who rendered it, and by frequently seeking forgiveness and supplicating for the sister.