Friend issues? Help???????

[Smiley]

basically, i couldn't go with her to the cinema the other day and now she's not acknowedging me and ignoring me. I didn't bail on her i already had other plans and i said i'd go the next day and she's in a mood with me and isnt even talking to me. I wasn't at school the other day because i was ill and when i came back she didnt bother asking me why i wasnt here, why i was ill or if i was ok etc. She also blocked me on facebook ;l It's not very nice and if I did this to her she'd be in a right mood! She's being really rude she doesnt even aknowldege im there and just leaves me out purposely when we're with our friends. Really not nice/pissing me of. is she a 'true' friend or is this just a silly fight? Help?