Of all the people in London, I have to run into you

You know how there's always one person in the entire world who you dread running into, a person so disliked that you'd willingly jump into shark-infested waters in order to avoid them. Well, unfortunately for me there wasn't a shark in sight for me to happily surrender to today. I'd placed an order at a store last week and was returning today to pick it up, the SA said she'd bring it right out so I started browsing. I sit down to try on some heels when out of the corner of my eye I see someone I vaguely recognise. I turn my head and realize that it's one of my old school friends. This girl, Hazel and I we have major history, we were great friends since we were kids as our parents knew each other and in school we had our bunch of close girl friends which we hung out with, there were 6 of us who were really close, typical BFFs and all that. When I was 14 we had a really stupid argument about something completely trivial, but we always had these arguments we wouldn't speak to each other for a few days and then it'd be as if nothing had happened. But the following Monday she walked up to me and said 'I'm not talking to you ever again'. I was stunned but to be fair I was really pissed of at her so I just let it go. By the following Monday she had some how turned the entire group against me. We didn't have any classes together so the only time we'd see each other would be during break time (recess) or when we had to change classrooms. They began blanking me when I'd wave to them in the corridor and when I sat with them during break time they'd ignore me. I confronted her about what she'd said to the others but she wouldn't tell instead just choosing to laugh. In the end I just gave up trying to convince them that whatever she had told them was a lie and realised that they weren't true friends or worth the hassle if they believed her without hearing my side of the story or confronting me about it. Funny thing is that I have seen her occasionally at gatherings when I've flown back to London and she has been overly nice to me, I however have been as cold as stone towards her, offering a curt 'Hello' before walking away from her, she in turn has turned around and bitched about me to anyone who'd listen. I still don't know why she hates me.
Anyway back to the present, so there I was hunched over trying to tie the buckle on the heel I was trying on and praying she doesn't see me. She begins moving around the store and I really wish the SA would hurry up so I can rush out of the shop and not come face to face with her. I slip my own boot back on but see that she's walked up to the counter and is paying for something. Crap! I implore that the SA doesn't emerge from whatever deep underground cave she went to for my order as she's been gone a fair amount of time. But... no, she pops out from the store room with my order, so I have no choice but to walk up and pay for it. I really wish I was wearing those big black sunglasses that cover up your entire face and scare little children. Alas, no such luck as this is England and I am not one to wear blackout shades when there is no sun. As soon as I walk up next to her she turns around and, I swear she must have some sort of supernatural sense of smell because she immediately registers who I am (her eyes widen) but strangely enough instead of acting all super-duper nice she looks away as if she hadn't seen me.
Aha! Ball's in my court now! She then looks at me again thinking I've looked away but I haven't, my face lights up and I give her a really warm smile and she just smiles weakly grabs the bag and rushes out of the store. Cue my turn to have a smug grin on my face all day long. Tee-hee!
Sorry that's been a major rant but I needed to get it out, that girl had made me so miserable when I was younger.