It is very rare for a teleclass to be cancelled or for a trainer to not show for a class as expected.  In the event of this happening, you have a couple of options

Go to the Forum

The trainer will post on the forum with work for students to continue on with.  You complete the work and discussion as required and then count this as a class.  

Attend an alternative option
You can attend this class at a different time option the following week, or at the same time at the end of the course cycle.