have booked a trip to Switzerland for me and my spouse, scheduled for September 15, 2013. I regret my inability to depart on scheduled date.
I think it is good if you introduced your booking in the introduction itself. Then they get a better idea about your booking;
This is with reference to my booking, ( give the booking reference) for the trip to London on the ???????? ?
Then express your inability to making it.
Kindly , have a meaningful topic in the subject field when you open a new thread so that you can earn more comments and feedbacks for your essays.