Ripped off

I was using the Airbnb site looking for somewhere to stay in London for a few days after travelling from Australia. I found an apartment in Covent Garden, perfect, dates were free. I next get a confirmation email from what I thought was Airbnb. This asking for payment for almost $1800. After a few emails back and forth, I was still waiting to be given the address of the property, by this time we had traveled to the UK. I then realized that I had been ripped off and had to find other accommodation. The response from Airbnb was basically, sorry can’t help you, it wasn’t booked through our site. What a joke, lack of security to protect the customer and no help after from Airbnb.