Yep it's zero respect because after they been told there bad behaviour still continues so they take no notice of our booking procedures.
Exactly. Most of the time I ignore. I replied to one 'you available' with 'thank you for your polite and courteous message, please read my booking instructions if you wish to continue'. A month later 'you available' so I cut and paste the same message. Another few weeks he actually sent the required information but I was fully booked, a few weeks later 'you available' again.... blocked