Hotel gave meal voucher in sterling amount as same figure in euro

I recently stayed at a hotel booked through my company. It was booked from England and in the email of the booking it showed the room rate in both sterling and euro. There was a meal voucher that was meant to be £35, but this was not converted.

Upon arriving, at reception I was given a card that had €35 written on it. If converted this would be ~€41.5. I should have questioned it there and then, or else order the value of more than €35 and made them beg me to pay the extra few quid. I felt a bit peckish later in the evening, and for the laugh I said I'd try my luck. The one at reception said no. Her first excuse was that they couldn't do it because the "rate is constantly changing" and therefore they couldn't establish a value. I asked her she could just give another card and write €10 on it, but no luck.

Below is part of the email. When I saw this initially I got the impression that I should have been given a card with said value on it, that I could use throughout the visit.

What do you think?