I reserved a stay at the Renaissance Arc de Triomphe in Paris during a promotion. It was advertised that bookings made during that period would get 5,000 bonus points. The bonus didn't appear, so I asked why. I was told that it was because I had reserved at "Stay for breakfast" rate, which didn't get the bonus, but if I had paid the lower price for "Discount rate", I would have got the bonus! Quite apart from the puzzling logic of giving a bigger reward to those who pay less, there was no warning of this condition when I made the reservation.