Shady Airbnb Host Says Room is Unavailable for My Daughter

I had booked an apartment for my daughter to stay for six nights from February 23rd to March 1st, 2017, with instant confirmation. I had checked with the host if it would be possible for early check-in as she will reach Melbourne, Australia after a long journey. He said he can make her stay in the apartment where he was staying with his brother and sister for two days and then shift to the apartment where I had booked. I queried him on the need to stay elsewhere for two days while I only needed a few hours of early check-in. He said that the apartment was not available until then and the listing had not been updated. I was not comfortable with this arrangement. Airbnb suggests that, in such situations, the host (and not the guest) should cancel the booking. The host had promised me that he will cancel the booking and that I will get a full refund. He did not cancel. He stopped responding to my messages and phone calls. Finally, I could only request a refund of AUD 843 through the Airbnb site (as opposed to the AUD 1,030 I had paid). Since then, I have been following up with the host, who continues to ignore my messages. There is no straightforward way of contacting Airbnb. The balance of AUD 187 should also be refunded to me. In fact, this created a major issue for me to make alternate arrangements for her to stay, while she was still flying, on the way to Melbourne. Thank god I did not let my daughter stay with a stranger (host) who turned out to be so shady.