I had recently been on a visit to Kolkata with my wife and I had to book a cab for a day. After searching for cab services in Kolkata, I came across http://kolkatacabs.com. The tariffs they offered seemed to be decent and we were able to book a cab (an Indigo) just one day before. But our experience with the driver was bad. He was not very responsive. But this is not my major complaint. He tried to cheat us.