How to get Airbnb to acknowledge a bug?

I'm an Airbnb host. Today we found a clear bug/glitch that allowed a guest to Instantly Book over another guest's accepted reservation on the same night.

The original guest and I have a decisive paper trail for their reservation. Not only that, Airbnb is still asking the guest to pay for the night that they have already promised to the second guest!

Airbnb support is refusing to acknowledge the bug. Worse, they are threatening the original guest and myself if we do not follow through with the new booking! I even got a support technician to admit on the phone that the product was not working right, but that his entire customer support team was not allowed to report bugs.

So I now ask the minds of HN - what do you do when a large tech corporation with terrible support has a glaring bug? How do you get a real person at the company to care?

And what recourse do I or other users have? What's the next step? Small claims court? A Tweet? I'm lost.