Man, I feel angry for you! The double booking is bad enough. Telling you she doesn't want to get a text from you later saying you're angry just adds insult to injury.

If I were you (and because I sometimes like to act out in a juvenile manner), I'd send her 20 texts about how angry you are. (I'm not recommending this, just saying that's probably how I'd act if I were you because I'd be SO MAD.)