We fell out because in a nutshell she ditched me last minute on a night out (after getting ready hair/makeup/clothes) and decided to go somewhere else with the same friends, despite spending all week planning the 'girlie night'. Then she never apologised or even explained why (other than the text "sorry off somewhere else") so I stopped talking to her. We haven't talked or said anything to each other since.
I think the other friends are a bit miffed that I've left the group, but she's stopped *****ing about me in front of certain friends because she knows they tell me what she's said.
She may well feel guilty and that's why she's acting *****y because she's too stubborn to admit it. What she did definitely wasn't nice but could you ask her to meet up for a coffee or something to talk about it now you've both had time to mull it over? Maybe you could do this after she's replied to your message about the money, as if it's in public she may not make as big a fuss.
Also about the money, that is a hell of a lot of money to lose, keep hassling her. If she won't give it back, you could always ask her parents. My old best friend was like this and she owes people hundreds of pounds and everyone hates her for it, no amount of nagging worked with her unfortunately. She still hasn't paid anyone back 3/4 years later, in some cases more.