Fly540 service is dreadful. The DMC I work for had booked seats for four customers on its service arriving into Kichwa Tembo airstrip in the Masai Mara scheduled to land at around 1030hrs. We were told by the airline to be at the airstrip at 1000hrs to collect our clients. At 1230hrs the aircraft still had not arrived and we were told that it had only just left Nairobi. At 1445hrs there was still no sign of the aircraft and Operations were no longer answering our calls. We finally got through to be told the aircraft would be landing at 1530hrs. Needless to say at 1530hrs there was still no sign of the aircraft and no explanation forthcoming from 540 as to how a flight that takes on average 30-40 minutes from Nairobi to the Mara could have taken more than three hours. Only a week prior to this incident we had customers travelling back from the Mara to Nairobi and 540 told us to be at the airstrip at 1100hrs. We arrived at the airstrip on time only to be told by those already there that the flight had landed ten minutes early and departed within five minutes without even waiting for our clients or calling the lodge to find out where they were (which all the other airlines do). As a result our clients' itineraries were completely disrupted and we were forced to provide another night for them at the lodge at our own expense as none of the other airlines could accommodate them.