@Anouk25 if you cancelled the reservation yourself (you should never do this!), one of the punishments for hosts is that your calendar will remain blocked for those dates, so you can't rebook them. If this is what happened, you can contact Airbnb aand explain that the guests was asking to contravene your booking requirements and maybe they will open up the dates.
If you didn't cancel, tell the guest that as she didn't read your listing information and was asking for a reservation that contravened your booking rules, that it is her responsibility to cancel and that she will receive a full refund if she does that within 48 hours after she booked.