When my fiance and I stayed at a place in Paia on Maui, the place looked immaculate from the pictures. But when we got there it was full of cockroaches. We had literally just gotten in at like 4 pm, put groceries down on the counter, and the little buggers were on them almost immediately.
We were exhausted and didn't have the energy to really do anything after our 6 hour plane flight. The hosts came in and tried to resolve things first by removing all the appliances and then by offering us a bribe. I had documented all of this on the AirBnB website via private messages, taken pictures of the cockroaches, and found a can of bug spray(the hosts knew they had an ongoing problem and still rented to us!) to spray the roaches with. They were falling out of every crevice that I sprayed in the kitchen.
We ended up spending a very restless night there, and in the morning I found a single roach in the bathroom. We were going to move out the next day, but ended up scrambling to find a hotel room in Maui that afternoon after driving the road to Hana.
When I called AirBnB to report the cockroaches the representative basically said he couldn't guarantee me any kind of refund, and moreover that I should be used to staying in "less than clean conditions" as a bachelor who has traveled for business. I was flabbergasted.
They eventually got us a refund but I have never had such a terrible customer service experience from any company, period. I will never stay in AirBnB again. Evidently they don't enforce any standards of cleanliness and they take all hosts at their words as to the fitness of the property. The CSR that initially handled my case was a huge asshole and made me feel like he didn't care about me at all. The later CSRs were better. Staying in an AirBnB was the most stressful vacation experience I have ever had and I will never trust them again.
As an aside, you should make it a point to call their support line during the hours of business in the EST or CST timezones. Their day shift CSRs actually seemed to care about the problem. But their night shift appears to be an overseas call center, and they treated me like shit.