I had done the reservation for the wrong date by mistake (aim for the following date but reserved for the same date at 21:00) , and directly call him. Rather than cancelling my reservation, he told me to contact with Airbnb. Thanks to call center, they help me. On the other hand without doing anything J charged 70 Euros. We did not stay, so I have no idea about the location or any other properties of the flat. So check the date once more before finishing your reservation ;)