I have no idea if they went out of business, I would assume not, if you call you can leave a voicemail but they never call back. I called like 5 times and gave up, others have complained about the same experience.
Sorry to inform you that i have tried numerous times to contact them through their website and phone calls and never got a response. I have seen that others have had the same non response. I wanted to use them also because we had a great experience with them 3 years ago.
Besides UBER, LYFT or cab are there other transportation companies that are in Miami to pick us up at the airport, take us to the Holiday Inn Port of Miami; pick us up at the Holiday Inn take us to the port and after the cruise from the port to the Miami airport?