I asked to talk with the manager, 'today is another day' he said. After the tour I was very disappointed as I knew that they asked again for the fee. Nobody in the queue accepted (there were groups of several people who wanted to join together), so my partner proposed herself (I had been at the Upper Antelope that morning for a photographic tour with Adventurous Antelope Canyon Tours, which I definitely recommend). After about 30 minutes somebody did not show and one spot got available. All the tours were sold out thus we were said to wait in the queue. The day after we went at Ken's and asked again. I was aware of the cancellation policy, so that response was expected. We wrote an email before the tour to ask if they could move it to the day after but we were said it was not possible.
On the way to Page a tyre got punctured, so we had to stop, replace it with the spare tyre and then find a place to fix it. We booked the Lower Antelope tour with Ken's at mid August (2 adults + 1 infant).