how to contest a quit claim deed

[Mike]

hi when my grandfather died the land was split up and one of my aunts deeded her portion my other aunt and my dad did not my grandmother also did not.

Grandmother received 20 acres, aunt received 18 acres, other aunt 18 acres, my dad 18 acres (passed away) before my grandmother passed away my aunt quit claimed all of the land from my grandmother but it was not my grandmothers to give. My grandmother was sick and and forgetful and did not know what she was signing so my aunt told all of us my grandmother left no will. Also there was nothing left and we all got nothing but i know my grandmother left a will she told me so when my grandmother went into a home her house was broken in to.

Thank you for any suggestions.