Hostile, hateful Grandmother. Pure evil?

Long story short: I am an adult, and as long as I can remember my Grandmother never has had anything nice to say about her own daughter (my mother). She has 3 kids, but just despises everything about my mother. Can anyone else relate to this and just let me know how you deal with it? People who have met my GM and then my mom,a sk if my mom was adopted because of what my GM says about her. We have done everything we can to be a part of her life and she wants nothing to do with it. Mom and I recently flew down to my cousins wedding, and my Grandmother was livid that we showed up and said we ruined everything. Said it was her time to spend with that side of the family, and my mom should not have been there? I recently tried contacting her and she wants nothing to do with us. Not only that but my moms brother and girlfriend are now harring my mom telling her she needs to stop treating Grandma that way and to fix the problem. How do you make a situation better, when that person is so hateful they won't even hear you out? Just needed to vent and see if ANYONE can relate....