How to cancel future occurrences of an activity

Go to Calendars at the top of the dashboard. 

Click on the activity you want to cancel. 

Select Cancel activity. 

Set the Cancel all future instances of this schedule (not just this time/date) option to Yes. 

Note: This will cancel the current activity you have selected and all future instances of this schedule, which may include sessions within the schedule that are at different times and on more than one day.

Finally, click Update session.