You can raise a cancellation request from your Chargebee app.

To cancel your Chargebee account go to user profile (bottom left corner)  -> Manage Account -> Select the subscription -> Click Cancel.

Note: 
Only the owner of the account will have access to raise a cancellation. If you have a dedicated CSM/Account Manager, we highly recommend reaching out to them. If you have enabled your Live Chargebee site, you will need to access this page from your live site. 

To Reactivate/Resume using our Chargebee account you can contact Chargebee support.