My oldest friend since primary school has really changed. She acts really flirty and sometimes bitchy and some of my Friends and myself had a big fight with her last year... She promised to changed but she hasn't.

We all change through years. i think toi not the same, that you've been in primary school. My best friend became kinda bithchy too but I l’amour her the way she is, although sometimes I feel embarressed for her and sometimes she irritates me
Now toi have choice: toi can leave her and find new Friends ou try to l’amour her as she is. But toi can't change ppl. She only can pretend to save your friendship (though I dont think that's a good way)

lots of people change. i'd sit down at chat to her. maybe start off ther conversation par bringing some sweets and offering her one, as a starting point. then bring the subject up with her about what you've just told us. if she's a true friend she'll understand.

i'm having friend trouble at the mo too. this is what happened to me:

my bestfriend recently turned on me because when we were talking, i told her of this boy i liked, and i really did like him, he was amazing and i was totally made for him. my BFF a dit she'd help me go out with this boy, and she a dit she'd speak to him. i asked her if she was sure cos i was pretty confident i could do it myself, but i trusted her to help me out. instead, she turned him towards herself and i later found out she liked him also, but this was after i'd already a dit i liked him. she did not help me at all!! while she was talking to him she had told him all these terrible lies and fake-cried and everthing. now she is with him. i feel like such a fool for letting her "help" me. worst of all, i see her every jour at school, and i have to accept that the guy of my dreams is now taken; par my so called best friend, who pulls his tie and pokes him in the stomach.
also, everytime she sees me she rips my work, really discreetly so no one sees, ou tips water on my work, ou pushes me against the mur ou throws my lunch in the bin.but she never gets caught cos she's such a goody two shoes to the adults.
so i'm pretty sad at the mo. mostly cos of losing my guy. :,(

The real question is do toi still wanna be her bestie..... Because one of my frinds didi that to me and i forgave her tha 1st and 2nd time but the 3rd time i a dit enough is enough and i told her if she was going to keep treating me this way we couldnt be Friends anymore she a dit fine for a littel while i couldnt even look at her but now we are Friends NOT best firends not even close Friends just friends. so see if toi get anything from that!!

Try to have a serious talk with her. If things don't change, then she obviously doesn't care about whether ou not she's hurting you; I'm sorry.

well if toi gave her a seconde chance she should have stopped I wouldn't b her friend anymore

I guess she's jouer la comédie that way because people can change and maybe as she got older she started to care plus about other things explaining how she acts now (flirty & bitchy).
I think also that she keeps making promises that being broken to toi to pretend to reasure toi ou just to stop u from bothering her (no offence).
I got in the same situation before so I know how u feel