When it comes to bills...that is the only time I would contact him. I would send him a text about the charge. I would also advise him that you are only contacting him because he advised you that he had cancelled the flight and if it was cancelled, it wasn't taken care of by the airlines. It could be that the charge was cancelled too late in the credit card cycle, but he could have also forgotten to cancel it as well.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
