This went down about four months ago and I'm still missing her. Is there anything I can do?

In about mid February, my best friend and I had an argument. I was commenting on her facebook posts, and she was ignoring me, which I found very rude and it made me mad. And I was also mad at her before this keep in mind, because she had been very cold and distant to me during a summer community production we did together. Anyway, I still tried really hard to forgive her and be her friend, but she just kept ignoring me and I finally blew my top. This is what happened on facebook. Her post said how do you let go of something you love a lot, I said what are you talking about, she said my dog that is dying. I said I have had my dog since I was four and she is dying too. I said youll get over it, she said ditto. Then I said hahah shut up I don't even want to talk to you anymore. Then her sister jumped in on it and said I don't understand your comment please explain it to me, and I said if I don't want to talk to her then why would I want to talk to you. Then both her and her sister blocked me but her sister blocked me first. I waited about a month and then I called them and I said I don't understand why you blocked me on facebook, her sister said "sweetie what you said to us was really rude". She was like here lets see how you like it "i don't want to talk to you right now" then she hung up the phone on me. I feel like I didn't do anything wrong though, considering I replied to her sisters message on there on time and she never wrote back, and I wrote my "ex best friend" a message on there and she never wrote back. I mean she was replacing me all summer and ignoring me and stuff and being me I walked around sad all the time about it and she kept telling her mom I was depressed when obviously she never cared in the first place. Even after that I still miss her but I don't think she cares or ever wants to see me again, what can I do? I feel like the only way I would get anywhere is if I begged for forgiveness because they are so rich, snooty, and full of themselves.