Thank you so much for your thoughts.
The two bookings were from women with the same name, both had a husband and two children and both were planning mountain walking. I was corresponding with them via the reply feature on my email rather than the inbox so had not realised they were two different people as their messages were virtually identical. It was a freakish series of coincidences.
AirBnB took no responsibility for their mistake and left me to try to sort it out from the hospital. One of the ladies ended up going home.
I understand what you are saying about taking responsibility as a host but there was no indication that the number that was on their website was not toll free and I had hoped that they might help out as the whole situation was out of my control.
Perhaps it’s time for me to chalk this up to experience but I have felt let down by AirBnB.