I will try to keep this brief:
Three friends (A, B and C) said something unpleasant about a fourth friend of mine (D). I defended her. Two of the unpleasant friends (A and B) then fell out with me because I refused to join in with their bitching, and in a Facebook conversation involving the other friend (C) they told friend D that I had said these things. Friend C knows the truth and knows that it was all lies, and feels awful about it, but hasn't and doesn't plan to tell friend D the truth, and is happy for me to take the flack. Therefore friend D is no longer speaking to me either as she thinks I've been awful about her.
She is now in a friendship foursome with the others, even though she knows what A and B said, and I am out on my ear and none apart from friend C will talk to me.
I think it's grossly unfair that I have been ostracised in this way when I didn't do anything wrong and deliberately tried not to get involved.
I get quite upset when I see on Facebook that they are all arranging nights out and that friend C is going along with it and didn't tell the truth.
I know this all sounds like we are 12 years old, and I hate situations like this, but it's all really upset me.