Ha ha, that's superb - I can well believe it too... you do get some right muppets
Most of the time, you just have to 'suck it all in' and try not to let it get to you. But then again, very rarely, it is possible to 'get your own back':
In the Coffee Primo section:
C: Can I please have a coffee .... *mumble*
Me: Sorry, Sir, I didn't catch that... could you repeat that please?
C: Maybe you should try ******* listening then shouldn't you?
Me: Erm...... ooookaay.
*The order is completed*
Me: Here's your ******* coffee Sir, have a really ******* good day
The confusion on his face was priceless \o/
One more:
Me: Here we go, one decaff soya latte!
C: I didn't ask for decaff...
(For clarification, I was making the drinks, but I was told the order by another member of staff)
Me: Agh, damn, sorry Sir, I'll fix that for you right away *gets drink*. Here we are, very sorry about that Sir.
C: *snatches the drink* Seriously, it isn't hard to get a drink order right, are you stupid?
Me: ... well, you know, it's hard to really define stupidity. After all, I'm not the type to buy coffee at vastly inflated prices. Besides I'm not that stupid, I'm an aeronautical engineer, but hey, that's not rocket science is it...? Oh, wait. Enjoy your drink.
I'm not an aeronautical engineer, but it happened to fit where I was going with my rant