Shopping in aldi. Just had a basket load but in a half trolley. Headed to checkout - all quite busy at 5pm on a friday unsurprisingly - and chose the one that looked most empty. Manoeuvred into checkout easily (this is relevant). Dropped the 'next customer' toblerone thing on the conveyor belt and started loading my (basketload) of bits. Had no sooner put down my third bottle of wine (#friday) when a woman clutching two multipacks of bog roll said "no! I was here first!" grabbed a basket of groceries from the foot of the conveyor belt that were sat on the floor and started loading her stuff. 
Her basket was in no way visible to me and it was stationed immediately in front of the checkout in such a way that my trolley didn't hit it, if you see what i mean. I assume she had left it there because the velt was literally full when she'd gone off to grab her extra bits. I had no way whatsoever of knowing she'd attempted to 'reserve' a spot in the queue. Ignoring whether that's really ok in a supermarket queue (if it was I'd just put my basket at the end of a belt while i grabbed my last bits and bobs to save time 
)
I said "no I'm sorry you weren't here i was here first", placed another toblerone down, pushing her shopping along the belt as i did so, and continued loading my things.
She then started reaching over me, and pulling my things off the belt and throwing them on the floor and/or back in my basket. Thankfully she never threw anything hard on the floor, just some salad and loo roll.
Other customers were looming and the checkout lady paused what she was doing and i said very loudly "excuse me can we get security here" while she kept unloading my shopping while i kept picking it up off the floor /my trolley and reloading it.
No one did anything and while she continued tantruming i said "you're embarassing yourself stop it". At this point i clocked that the security guard had turned up and i said "can you please remove thus lady".
Then someone (maybe a supervisor?) appeared and said to her "can you please come to checkout three and we will open it for you" and she huffed over there with her basket while they opened up a new checkout for her and she sailed through past everyone queuing / being served.
When i made it to the front of the chekout (quite shaken, i must say!) a woman pushed forward with two pints of milk and said "I've just got these" and the checkout lady started serving her!!!
I'm afraid I'd had enough at this point and said "no sorry i was first" (yes - mildly ironic!) and when the checkout lady protested i refused to relent, and the chekout lady and the milk lady were all cats bum face.
Wtf?!
FAOD 1) if angry lady had said "sorry i was here first i left my basket while i nipped off to get some other bits" and was polite i would have let her past and b) if the woman with the milk had asked politely to skip the queue i would have said ok (maybe grudgingly because no one is so special that we can't wait our turn).
Sorry so long winded - this all happened in about 30 seconds (unfortunately apart from her being queue jumped by the staff).
My AIBU is this: is it ok to allow tantruming shop bullies to be aggressive towards other passengers and to reward them by opening a special aisle for them?!
I get that staff are not police and want to simply diffuse situations but wouldn't you (as staff) say to the customer who'd had her shopping thrown all over the floor "are you ok? Hope you don't think we condone thus behaviour we just wanted to remove the aggressive customer" - anything? Anything to make me feel human?
I left the shop feeling so upset and tbh a bit worthless.
AIBU to write and ask if they'd treat a white customer this way?