Sorry to hear that, tKf, but that's the way of it with these flying machines! After a few years in the aviation world, you get to learn to live with these kind of disappointements (which is what makes
actually flying such fun!!
For example, when I was learning in Canada and was just getting towards solo stage, I booked an a/c every morning at 0700 for 10 days in a row. I flew 3 times out of these (wx, sick a/c, etc) - finally soloed on the last slot!!
Take a good book (probably written by Mr Thom!!) to each of your lessons. If you can't fly, study for a ground exam and see if you can take it on the day if you're ready. At least you're getting something useful out of the visit!