Minor Annoyance

So I went to the supermarket last night after work to stock up on some
much needed food supplies. After a quick dash round the aisles I
arrived at the checkout and the beaming young lady at the till began
scanning my purchases. The total was 2,317 yen.

Now, if you live in Japan you probably know how annoying all the small
change can be, particularly the next-to-useless 1 yen coins. Pretty
much all the English teachers I know around here have an enormous jar
somewhere in their apartment brim-full of 1 yen coins which they can
do absolutely nothing with. The bank charges you to change them into
higher coinage, and it would be far too embarrassing to actually take
a sackload to the shop to buy something with them, so they just sit
there, unused. Consequently, I try and get rid of my small change
wherever possible.

In this case I wanted to pay with a 5000 yen note, but in order to
avoid being handed back a large pile of loose change I cunningly
fished out exactly 317 yen in coins from my pocket. Yes sirree, three
crisp 1000 yen notes were gonna be heading my way. The smug grin was
already forming across my face.

However, something was amiss. The beaming till girl had given me just
two 1000 yen notes, and had begun to count out mountains of change -
the transaction had gone very wrong. I looked up at the till screen
and to my horror I realised I'd forgotten to give her the ten yen coin
in my hand, and she'd begun counting out 2990 yen in change. Heavens
above!!! Quick as a flash I thrust the ten yen coin towards her with a
quick "sumimasen", but her reply almost knocked me to the floor: "[in
Japanese] I'm sorry, but the till says I have to give you 2990 yen in
change."

What?

She went back to counting out exactly 990 yen in small coins.

I was gobsmacked. Surely it would have been easier all round just to
give me a note? Was the till angry at me? Why was it making me suffer?
Several things occurred to me as I walked back to my car with the
massive ball of change chinking against my leg:

1) In Japan, the customer is always right. When I accidentally gave
her 2307 yen instead of 2317 yen the till girl automatically assumed
that I must have done it for a reason. Perhaps I just loved small
change, and would be ecstatic to receive 990 yen in small denomination
coins. Perhaps she thought I was going to a football match later and
needed lots of coins to throw at the referee. Or maybe she was just
too scared to tell me that I had given the wrong change because she
might have had to speak in English. Probably the last one I expect,
although I'd like to believe that she thought I had some sort of coin
fetish.

2) Although the customer is always right, the till has divine
supremacy over everyone and everything, and as such it MUST BE OBEYED.
Here endeth the lesson.

As I say, only a minor annoyance. But still annoying.