excuse me, how about do your job?

I went to get petrol on the way to School this morning. At the moment it's sitting a tad under $1.50 a litre, lucky us ($5.70 a gallon). I filled up the tank, then went inside to pay (that's how we roll, here. No pre-paying or weirdness for us). The lady on the register was chatting with her co-worker, as I'm standing there. I'm impatient. I wait. There's nobody else in the store, just me.
I wait.
I'm fairly certain I waited about 30 seconds and it wasn't like they were talking about important things like how to put out a fire in the back room, or what to do if there was a crocodile in the store, or how to deal with a wasp nest on the fuel pumps.
Eventually she comes back to her position, no "Sorry" or even a hello, or a smile, which I'm fairly sure is part of her job.
She growls:
"$56."
I put the discount card out for her (supermarket scheme, non-Australian people. We get 4c off our petrol if you shop at one of the two big supermarkets then go to the appropriate petrol station.), which she scans.
"$55." She mutters. I'm a little peeved at this point because I was running late and she hadn't acknowledged my presence. I hold out my card, and she basically rolls her eyes and, turning as she speaks, vaguely says:
"Swipe your card"
And is back to talking to her coworker.
So I wait for the machine to say 'swipe'... and it doesn't.
I wait a bit more- sometimes they're slow.
And now I'm annoyed because not only is she one of the worst petrol sales-people I've seen, but she hasn't been bothered to do her job well enough to hit the 'enter' button on her screen to activate the card machine.
So, I say:
"Um, I would swipe it, if it worked." And yeah, I sound like a bitch when I'm saying this (Ok, picture a bratty 16 year old, rolling her eyes and jutting out her chin... now scale back the image a liiiiittle bit, and that was probably the tone of voice I used.
The lady looked stunned. Like, why was I suddenly being rude to her!? When she'd been nothing but polite, and helpful!! She literally looked at me like I'd just called her a f---tard, for no reason.
"Sorry doll!" She says, mashing the screen. "Sometimes it just goes to sleep."
I think I rolled my eyes, mutter "no worries.".
"Sorry about that."
And I'm thinking: No, you're really not. You're only sorry because I snapped at you and you suddenly came round to the fact that I'm actually here, trying to get some damn service, and I interrupted your chat. 

And then she told me to have a fantastic day.
Laced with sarcasm.
You know sometimes when someone's been rude to you and you're super extra nice just to 'be the better person', or make them more angry, or just rub it in that you're nice and they're a bitch? Yeah, she tried to pull that on me. And I am not a bitch, people. I am not confrontational. I hate confrontations. HATE. So for me to actually say what I said speaks volumes for how freaking peeved off I was.
But then I went to school, and the girls gave me hugs, and I got to go gardening with some of them, and then the grade 5/6 kids went horse-riding. But I didn't get to ride. But it's ok... it just made me miss horses and riding like crazy.

Now I'm off to the gym. I'm going to try and change my running style. Or, start to change. Fairly certain it won't happen overnight.