Not at port & refusal to issue refund

We booked services with Zip Transfer after a cruise in Barcelona. The boat docked at 7:30AM but did not clear with port authorities until 8:40AM. We left the boat immediately and gathered our bags which were readily available so we were out of the building at approx 8:50AM. We didn't see a driver so spent 10 mins searching for him and waiting. I finally called their office and they advised me the driver just left 2 mins previously and refused to come back. I told her I had been waiting and didn't see anyone. I then asked for a different car as there were 8 of us and we needed the carseats I booked. They refused saying they have no other drivers available. We ended up taking two taxis to the airport and made our flight.
When I inquired about a refund, they advised me the driver was there at 8AM and should only wait 10-15 mins before leaving but he did me a favor by waiting until 9:03AM. I advised them I have no authority on when I could come off the cruise boat. We left as soon as they allowed us to do so. They were unsympathetic and said they would not issue me a refund.
So basically, if you book them, you must book them for a later time when you know your boat will be cleared for disembarkment and you must be sure to get to them within 10-15 mins of your time. There is no understanding on their part if you are stuck for reasons beyond your control.