LIke you say, I don't see any indication in your listing that you've ever canceled. I suggest starting with AirBnB's Twitter account, @AirbnbHelp (they respond quite quickly and will, if necessary, escalate you to email or phone support. Don't send them a standard tweet, but send them what Twitter calls a Direct Message. No character-count limit and seem by them only.
That's really their preferred initial contact method.
As an alternative, you can also try this, although the exact sequence tends to vary depending on your country, etc:
Go to the Help Center and click on "Resolve Issue" at the bottom of the left side bar.
At the bottom of the page, click on the bar saying "My question is about something else".
"What is your question about" will pop up, Choose "Hosting".
"What can we help you with" will pop up, In the dropdown menu, choose "Account and Profile".
At the next dropdown menu, choose "Review".
At the bottom of the page, click on the "I still need help" button.
Choose an option in the next dropdown menu.
A message box will pop up and you can choose either live chat or email Airbnb. (Some users don't see the option to use email.)
