@Emiel1
Yes, it makes sense if the payment has not gone through, the guest is given 24 hours to make payment and the calendar is blocked in the meantime. That is not so strange, although I know a lot of hosts are not at all happy about that set-up.
What happened here though is that there was no booking request on my end and so I definitely did not accept it. When this showed as 'guest has 23 hours to pay' or something to that effect, and my calendar was blocked, it was still marked as an enquiry from my end (at the point at which I called CS) and then later changed to 'awaiting payment'.
What concerns me more is that CS told me that from their end it was showing as a request accepted by me. @Emiel1 may be right that the CS rep was wrong (he wasn't sure what was going on and said he had to check it with another team and get back to me) but, in that case, would I then get a booking request once the payment was sorted and have 24 hours to accept/decline? Why is the calendar blocked before I have accepted?
Or, would the booking have been confirmed without my consent once the payment went through with CS telling me that it was showing as confirmed by me and therefore I face hefty penalties if I cancel? Although the percentage is lower as the booking isn't until January, the penalty would still be pretty hefty for a two-month booking and what if the booking was for stay in a few days' time?
That is what really concerns me. It's not like I am going to get answers from CS as the rep said all he could do was to report it but you know these front line reps don't get informed about technical glitches, let alone told when they fixed.
In all my previous experience, the host has to accept or decline before Airbnb try to take payment from the guest. How can they even start the payment process when the host has not accepted the booking? The booking was not confirmed only because the payment failed, not because I declined it.