Hello @Riccardo152,
this is a forum where hosts help each other from their own experience. It's not Airbnb support so people here don't have accesss to others' accounts.
To permanently deactivate your listing log on to your account. Then click on "Host" and then on "Listings" in the drop down menu.
Then click on the "Manage listing" button for your listing. Then scroll down a little and click n the "Edit" button in the "Listing status" section just below your listing's title. Then click on the "Permanently deactivate listing" link and then on "Save".
You won't be able to deactivate your listing if you have still have confirmed reservations.
How do I snooze or deactivate my listing?
Steve.