Bookings - Multiple attendees

Hi Guys,

I've setup a bookings page with an appointment to allow multiple attendees. This is all working great, unless an attendee makes a mistake and needs to change their appointment time. What happens here is that all attendees with that time are moved.

I cannot find a way to cancel or move an individual attendee from a booking even in the back end. Please help urgently as this is for a very important occasion - my partner's 30th Birthday!