hello @Cecilia46 and welcome to ABB CC from New Zealand
Should you ever receive an Enquiry like this, or a WhatsApp enquiry, ( ABB now flag WhatsApp msgs with an alert which is good to see) immediately use the " Report User " option at the bottom of the reservation details page.
I had yet again, another WhatsApp enquiry today for a 3 week stay which I reported it as Spam, as you should do to & Declined the booking request.
When one Declines the request there's 2 boxes, one to reply to the Guest and in this type of situation it's best not to engage in conversation and do as @Mike-And-Jane0 suggested and simply place a
"dot' symbol.
The other box is for feedback directly to ABB which I also provided as my calendar had also been blocked this week for reasons unknown to myself and it may be interrelated.
Make sure you check your 'Views' and see if any dates may have diagonal lines though it suggesting someone may have checked dates and made a booking which didn't go through, nor perhaps did they have any intention of going through with it, and also report that to ABB Customer Services for following up.
They should be able to check the IP addresses and ensure they are held to account.
All the best