Cancel a Receipt
Here's how to void a receipt:
1. Click on the scheduled appointment
2. Click on More... 
3. Click Cancel Receipt. *Please note that the receipt number initially generated cannot be reassigned to another appointment and will therefore be lost
4. Click Save 
By consulting the client's profile, under the Visits and payments section, the receipt that had been saved will no longer be there:
Before cancellation:
After cancellation: 