This article also covers
When do subscriptions automatically cancel in Chargebee?
There are six ways in which a subscription can be canceled,
When you manually cancel a subscription via Web Interface
When your customers cancel their subscription from the Customer Portal
Due to non-payment in the Dunning process
When the number of billing cycles reaches zero at the end of a renewal period
When subscription comes up with renewal with no credit card on file and Auto collection ON
For more about charges during cancellation, click this link
Related articles and Documentation
Can I reactivate a canceled subscription?