It always amazes me that people expect not to be charged for missed lessons. Does this happen in any other activity? If my child is sick and misses her ballet lesson I don’t expect a refund for that class.
Most trainers / coaches will offer make up lessons for the occasional one cancelled with advance notice, and that’s fair. But a last-minute cancellation? Definitely something the rider is on the hook for IMO.
When my horse has been off for several days or even weeks, I don’t expect a refund of my training fees. What I do expect and appreciate receiving is that in days I can’t be there, my trainer or her staff will hand walk, lunge, wrap or provide whatever care is needed during the lameness.
At our barn we bring in, tack up and groom our own horses for our lessons - staff prepares the horses whose owners aren’t there that day for the trainer. So if I cancel my lesson at the last minute my horse might not get ridden that day. Trainer will not have budgeted the extra time in the day’s schedule for bringing in, grooming, tacking/untacking and cooling out my horse. She and her staff should not be expected to work extra hours simply because I cancelled with no notice.