Medtran, All I can tell you is what finally worked for me. I had an extremely difficult Mother who was a hateful, hurtful, uncaring, narcissistic individual. Her own mother was also difficult towards her. My Mother treated all three of her daughters with the same disdain. She would call us on the phone, which we got skillful at ending the conversation quickly, or she would write us venomous letters. I usually ignored her letters. Finally, since ignoring her letters was not working for her or me, I chose to write her a letter. I started and ended the letter with the same idea, Mother, no matter what you say to me or what you do to me, I will always love you. In between those sentiments, I explained why the things she wrote to me were untrue and hurtful, item by item, mostly from the last few letters she had written to me. It took me a few days to get the courage to mail her the letter, but I did. What happened next was totally unexpected. My Mother called me to apologize profusely and repeatedly. She said she had no idea the things she was saying/writing to me were hurtful. Now I found that unbelievable that she could not understand that, but that was how her twisted mind worked. I think writing the letter to her gave her a chance to reflect on her behavior, before we next talked on the phone.
Good luck with however you approach this problem.