Then change the fee schedule to reflect this.

The problem I have is that your system does not serve 2/3rds of the customers. Your best students are pretty much self-taught, so why do you charge them for all of the your time. The poor students do not show up either, so why are you charging them for your time as well?

I am not critizing your specific method of teaching, just your fee schedule. You admit that your services are basically useless to 2/3rds of the sutdents, yet you charge twice that of a personal tutor service for each and every one of your students. That is where the anger is coming from.