I have a client who is cancelling her wedding. She's paid her retainer, which I'm letting her apply to a portrait session in the future. How do I do this in ShootQ? I read another question where they said to create and "book" a session for her, then cancel the wedding. She hasn't decided on the date, it's an open-ended portrait option for her. I need to get this canceled, so it won't send her reminders for future payments, but I do NOT want to totally delete her out of the system.