Air Ones cancelled 87 flights early this week, which left 9, 000 passengers stranded.
At Milans Linate airport 10 flights were cancelled on Monday and passengers at Rome Fiumicino, Bari Palese and Torino Caselle all suffered long delays and some flight cancellations.
Air One - the largest privately-owned airline company in Italy - could face fines of up to 50,000 by consumer rights watchdog Codacons.
Enac (the quality control organisation for passenger flights) is accusing Air One of failing to provide assistance to passengers and is demanding refunds and compensation.
The airline company blamed bad weather conditions, service delays in Greece and Spain and the unavailability of a number of aircraft due to technical problems.
However, trade unions and Air One pilots agree that the main problem is that the company does not have enough staff to deal with the increase in scheduled flights for this peak period.
In the meantime, Air One has blocked the sales of tickets to certain destinations in order to give precedence to passengers still waiting to board their flights. The airline company promises that all will return to normal in the next few days.
Air One specialises in national flights, particularly to Sardinia as well as new international destinations such as Athens, Casablanca, Ibiza, Palma de Mallorca and Copenhagen.