I've refused to fly a number of times.
One was mid-trip on an out & back charter. Pax didn't show for the return at the agreed time. Waited a couple of hours. Phoned them multiple times. Texted them. Finally answered and said they were on the way. Waited more hours and was running out of duty time. Phoned again. The phone was answered & then hung up on me. During that brief window I heard loud bar/party sounds.
Meanwhile the office was also trying to contact them. Eventually they arrived back at the airport but I was out of duty hours. I explained that I was no longer permitted to fly and that we'd have to stay overnight.
I believe the hotel bill was added to the customers final bill. Served them right.
I've also declined trips due unservicabilities or weather.