I don't want to go into too much detail.
Essentially, I had an argument with my best friend - we were both tired and frustrated, and it was over something petty, but she was incredibly aggressive/sarcastic and it really shocked me.
I apologised later on for my behaviour - I like to sort things out quickly, and not hold grudges etc. It was a genuine apology because I had overreacted, but I did ask if she understood why I was upset.
She 'apologised' in a sarcastic and quite angry way, sort of a half apology of - 'but I didn't do anything wrong' IYSWIM.
WIBU to not talk to her until she apologises properly? It all seems very childish and like it belongs in the playground, not between two grown women.