One plus one equals three

'Could I have a whole chicken, but could you trim it into half for me, please.'
'I can't do that'
'I'm sorry?'
'If I do that, I would have to charge you for two halves, instead of a whole chicken.' That would be, I don't know, 70 pence extra?

I frowned. 'Really,' I replied, flatly.
'I'm afraid so'
'Well, I'm still buying a whole chicken, I don't see anything wrong with cutting it into half'.
'I can't do that'
'Fine, give me a whole chicken instead.' I was extremely annoyed. I had been buying the roast chicken on and off for the past year or so and never faced this rubbish before. 'Is this recent?'
She muttered something that vaguely sounded like yes.

The next time I was there, the counter was staffed by different people.
'Could I have a whole roast chicken, and could you please trim it into two halves for me?'
I got two halves, as requested. And charged for a whole chicken, not two halves.