If you're happy to discuss a concern/question with Airbnb via their website's messaging system, following is the obscure path to achieving that:
1. When logged in to your airbnb account, click Help on the main menu.
2. This takes you to the Hosting Help page. If you can't find the answer to your question here (you probably wouldn't be on this forum if you could!), scroll to the bottom left and click on the lonely little "Give Feedback" link floating around all by itself.
4. This brings you to the "How are we doing" page. Answer the questions listed there as indicated below:
Q. What would you like to do? Select "Give Product Feedback" OR "Report a Bug" - whichever best applies to your situation.
Q. I'm using Airbnb for...? Select whatever best applies to your situation (eg, Hosting, Travelling...).
Q. What's your feedback? Only select "Other" (all other options will send you backwards and make you even more frustrated than you already are!). This will open up a "Tell us a little bit more" box where you can detail your question/concern.
5. Once you feel you've sufficiently expressed your issue, click "Send" and an Airbnb representative should get back to you.