http://www.thefreedictionary.com/defaulter
Failure to perform a task or fulfill an obligation
Phase 1 can only "skip" 2 lessons. If you skip a 3rd lesson, you
must do a make up lesson to cover the a lesson that you had
skipped. Since you skipped 3 lessons, you are considered in
defaulting your RT and will be charged. And after being charged and
fine $50, you will need to rebook your RT on the spot.
I am not sure if you need to repeat phase 1 or can go to phase 2
straight away.