Search Results: breaking up for no reason

Me and my now ex boyfriend / childhood friend are no longer dating or friends today making it a year... he left me without a reason, just texted saying " I'm breaking up with you this is the last time I'm talking to you"
I felt alone... I lost my best friend that I had been friends with for a long time and dating a short time ( we were not happy but we made it work at least I thought so) I never heard from him again. no body wanted to talk about it. His friends acted like nothing was wrong and were nice to me... at first.
Okay fast forward to a year later. I still had no contact with my ex (and I tired to contact him during the break up twice because I wanted my closure but I never got it. No answer. Nothing. so I gave up thinking we just grew apart.) but decided to keep him as my friend in fb because it wasn't hurting anyone... at first.
I'm dating a much nicer man and very happy with my life until I received a comment from one of my ex boyfriend friends stating I was cheating on (ex boyfriend name here) which was a lie (it made me angry and sad hearing her accuse me of doing something like that to someone who used to be my best friend... I felt disgusted I wanted to yell I wanted to scream but I didn't) and just saying a lot of stuff I did in the past that happened years ago but I still do regret, but it was things that didn't matter any more because it happened years ago ( I'm not proud of my past but I am happy I have changed for the better) I did not cheat on my ex or my current boyfriend.
I knew her, it was one of my ex boyfriend female friends (he has like 5 of them )
Who was nice to me during the break up but now is showing her true colors Now that I am happy and moved on and I unfriended my ex not wanting anything to do with him or his female friends... I blocked her but feel like It didn't do anything. I would like to know why? Why do female friends do that?