No sorry, I don’t remember, it was arranged through my hotel, but you can search online and check reviews of suppliers. I have generally been very pleased when I have used a transfer service, but I have also been happy when using taxis, either arranged by hotels or from the official taxi ranks. There is nothing wrong either with taking the train from FCO to Termini, I have done that several times but unless you are staying in the Termini area that leaves you still needing a taxi from Termini to your lodging.