@Petra644
Have you changed your password on your account now? Do check your personal settings and remove any payment methods attached to your airbnb account.
If you use the same e-mail and password combo for signing in , it's likely this information was breached elsewhere. Of course, it's better to use unique passwords for each key account you may use.
It appears a criminal has tried to cuckoo your account. Setting up a new listing is a known way to try to milk stolen credit card details by making fake bookings to obtain payments.
Existing accounts don't undergo the same scrutiny as box fresh accounts, so that's why there is some attraction to it.
It seems a crude attempt as your messages were not diverted elsewhere, or your email perhaps wasn't bombarded with sign-up messages in an effort to conceal changes to your account.
I understand it's frustrating not receiving at least an acknowledgement after reporting this. Hopeful someone somewhere will read about your incident.