The same thing has happened to me too many times at IHG properties in Australia. In my case it's because they have usually upgraded me to a better room. And sometimes, due to heavy bookings, they have not been able to reverse the 'mistake'. They don't always see the bedding preferences it seems. I always send an email to the hotel now to confirm it.

But when the 'mistake' couldn't be reversed, the hotel has always offered something - usually from the restaurant or bar.