why is my property not listed ?

i keep getting a message asking me to verify my location with a code that they have sent via mail?? but have not received any letters/mail from booking.com? how the hell do i verify my location with this unique code if i ha my property is not listed and booking.com says I need to verify my location using the unique code sent via post to me, but have not received anything at all ? and I keep asking them to resend it.