@Cara19
Cara, although you have been an Airbnb member for a time you seem to be new to the hosting side of the company so I will go into a bit of details here, so that you can understand what is happening.
Cara, this has been an ongoing problem which Airbnb do not seem to have rated as important enough to fix for more than a year now, and what you are experiencing is happening to a considerable number of other hosts as well....you are not alone!
From what I have been able to learn, what is happening is, you have your booking calendar open to accept bokings for three months which is fine if you don't want to accept booking further in advance than that. But, if you block out dates more than three months in advance, as the rolling calendar comes to those blocked dates it automatically unblocks them and opens those dates for booking. It was fine before 'Instant Book' came into use because you had to approve every booking request but now, if you have Instant Book turned on people are going to book dates you thought were not available. I notice you are not using Instant Book but you will still get requests for dates as that window comes to them and opens them!
The best way around this problem Cara is to set you booking calendar to 'All Future Dates' which means there is no longer a rolling calendar to open dates, and once you have done that set a start and end date for days that you want blocked and that way these days should stay secure for you. You can access feature under your 'Availability Settings' which is on the right side of your 'Calendar page'. Go to 'Booking Window' and from the options available select 'All future dates' and this should solve your problem.
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If you decide to use Instant book and bookings are resulting from dates you have blocked, don't cancel them Cara, you will be penalised if you do! Get onto Airbnb on the following phone numbers...... +1-855-424-7262 / 1-855-4-AIRBNB (toll-free) and they will take care them for you, they are doing it often enough.
It is disappointing that more than a year down the track this problem has not been attended to. If it was something we as hosts were doing wrong Airbnb would simply delist us if it kept happening, but we are all hopeful that sooner or later the company will put the resourses into actually fixing this problem and help us as hosts to put on a more professional face instead of continuing to mess ourselves and guests around!
Just one other observation Cara, you have a beautiful Condo but you are going to serverely limit your market by charging a minimum 8 person price of $1,460 au per night for a stay. You would be considerably better off starting with a minimum 2 or 4 person price in the $200-$300 bracket and then charging for extra people up to your maximum 10 or what ever!
Just remember, 50% of something is better than 100% of nothing...Hope this helps!
Good luck Cara....cheers.....Rob