J.W.
Usually these stories have a hint of meanness but yours does not. Why should those girls have played with your daughter? Just because they are there and she is there doesn't mean they need to play together.
From time to time this happens with my daughter, I tell her not everyone is going to like you. There are also times she doesn't want to play with another child, I don't make her.
Sorry but the other mom was right and calling her daughter a bully was the only rude thing said.
I am sorry I know this seems mean but I really do think you were the only rude person on that playground.
Maybe it is because my younger son has Autism spectrum so he really doesn't get social cues that I see both sides of this. A lot of kids don't want to play with him because he seems strange. No worries, he is strange. Yet I explain what is going on and am always amazed how many of those same kids would take him under their wing. Even if they didn't I wouldn't call them bullies for it, they are just kids.