Leaving Ukraine, I ran into an unexpected money problem

Arriving early – true to form – at the train station, I tried to get rid of my excess hryvnia. Having 50 euros worth of odd currency didn’t seem very useful, and apart from hanging on to a few singles, their appeal as souvenirs was limited. All the exchange boots seemed to offer similar rates, so there was little point in shopping around. I approached the first one that was open and handed over my wad of cash. Exactly 50 euros, only they were obviously not in euros – yet.
The question that came back certainly alerted me as to why I should have held on to that paper slip I got in the Irish pub/exchange office: “Receipt?”
I said no and shook my head for emphasis, which only prompted the lady at the counter to hold up a form I’d never seen: a currency exchange certificate. It was blank and seems to come complete with several layers of carbon paper. I gave here my best blank look, and the certificate disappeared from view. It was clearly something I was meant to have gotten from somewhere else, well in advance.
The not-so-nice lady was set to offer me one final straw: “Ukraine passport?”
I was tempted to say that if I had a passport, I would most likely have spoken to her in Ukrainian, but we didn’t share enough of any language for that kind of complex remark. She just shook her head at my bright red Norwegian passport and waved me off.

Downcast, but not defeated, I decided to try again at the airport, hoping the rules might be different there. Alas, they were not. I went to the whole ritual again, with someone whose English was even less developed the the lady at the train station. I resisted the urge to make a sarcastic remark; again the lack of a common language would have left her with only my passive aggressive tone.

As I was leaving, a man with the right kind of passport and a 100 euro note appeared. I was mulling how to ask him to break down his 100 into two 50s and engage in some black-market exchange, but once again came up short in the language department. And didn’t have the bottle.
Then suddenly, I was saved by the bell. Or rather by knuckles on glass. The woman at the counter was talking to the man and pointing at me. He shrugged in the possibly universal fine/I don’t care/whatever manner, and then she addressed me. I really only understood the “hand me your money” part, and missed the “wait until I ‘ve dealt with this gentleman” part. He got hryvnia for his euros, and lo and behold: With an extra copy of his passport, I got euros for my hryvnia immediately afterwards.
In the face of archaic exchange rules it seemed to matter less whose passport was presented, as long as it was the right nationality.