هل توجد آية قرآنية أو حديث نبوي شريف يؤيد المعنى بأن الله قد أوجد رجالًا على الأرض لإعادة الحقوق والمظالم لأصحابها؟

There is no specific hadith that explicitly states this matter. However, one can infer it from the hadith: "Help your brother, whether he is an oppressor or oppressed," and from the encouragement for a Muslim to aid his brother, as well as the clarification of the danger of injustice and the obligation to repent from it and seek absolution from the wronged person if the injustice originated from the administration.