I did have a friend like that and I only dealt with the situation 2 weeks a go. We have been through the thick of it together, she has done a lot to help and support but she is too negative and gets bitterer each day.
The first time, she was sick and I got scared because we talk every day and I hadn't had news from her. I got worried so I called, not aware of any wrong in our relationship. She insulted me on the phone saying I bothered her and hung up on me. After two weeks of silence, she started calling me again and apologized. I was hurt and disappointed but I believe in forgiveness.
The only thing is that you don't forgive to be wronged and hurt again. She did it two more times, the last time two weeks ago.
I politely told her I would leave her alone and she could try reaching me when she really feels like being a friend.
She is not a loving person at all and wonders why people don't love her or why she deals with so much negativity...she produces it herself and shares with people around. Now, I am still hurt because of the feeling of betrayal I had the first time I realized to me that she didn't have affection for me but something opposite. Her heart revealed itself that first time and then again.
Whatever it is for her, I need to have real friends around, friends I love, who love me, I respect, who respect me and we need to be able to trust each other and have each others' back...or it is not friendship.
Please, do the same, she is not your friend. They are good people out there who will enjoy your friendship and have your back.
Love and peace