AITA for ignoring phone calls from an ex friend

I was uninvited to her birthday party by her after another friend of hers invited me via Facebook. Over the last couple years, my friend quit inviting me to meet for cocktails and do other things with her. She also did this to another mutual friend. We discussed it several times and both of us have hurt feelings over it. I chose to walk away and be done with her. My other friend keeps trying to reach out to her, but always ends up getting her feelings hurt. When I got the invite, I didn’t rsvp because I didn’t think she would have invited me herself. About 3-4 days before the party, she said she was calling to chat. But, she ended up uninviting me to her party by saying things like, “I’m not looking forward to this party because…entertaining everyone, certain people invited don’t get along, people in town, don’t care for the venue. She had plenty of reasons to explain why I shouldn’t come because SHE will be so stressed, etc. Since that phone call, she’s tried calling multiple times and texting me to see if I’m okay and ask why I haven’t responded. Aita for not responding with an answer? Should I answer her call and tell her I don’t want to be friends anymore (she’s the one that started excluding me in the first place). Or should I continue to ignore the calls and hope she figures it out on her own? I do feel bad for ignoring her, but I guess I’m just trying to protect myself from future situations like this one. Any advice is appreciated.