@Kathryn-And-Colin0
On the surface of it.....scam! a few points:
1/. What is the reservation confirmation code? It will be in your message stream with this guest on the left side of the screen just above the payment details and will look like this.....HM35HBDEN9
2/. Airbnb will not call you or suggest you should any communication outside the official site.
3/. If this guest actually has an Airbnb profile, in the message stream on the top right corner of each message box you will see a small flag, click that flag! That will do two things. it will bring that users to Airbnb attention for further action and it will block that user from having any more contact with you through the Airbnb site.
Kathryn and Colin, we either use this system, or we go off and do our own things.....what is it going to be for you?
Here is the contact link should you require more help....
https://www.airbnb.com/help/contact_us
Cheers.....Rob