Hey @Nidhi_sharma, there are a few ways to remove these appointments in the Infusionsoft app. One way is via the “My Day” calendar as show here. You can also navigate to a contact record, and open the appointment you wish to remove, then click the “delete” button.
There is no disabling appointments specifically, instead the lock out is more global and would affect other api calls. I suggest reaching out to schedule-once to see what they can do prior to the appointment being sent to Infusionsoft, as it does not make sense to keep cancelled appointments.
We do have a way to delete appointments, which schedule-once can use to remove those “cancelled” appointments.