Flight delays, trouble getting refunds, cancellations, and ballooning airfare are increasingly pushing U.S. travelers to file complaints with airlines this year.Stacker ranked airlines by those which received the most customer complaints in March 2022, based on data from the 2022 Air Travel Consumer Report, released in May 2022. Data points covering the total number of complaints and passengers served during that period are included for each carrier. The ranking was based on the number of complaints per 100,000 passengers to account for the varying sizes of airlines.In March 2022, there were a total of 2,414 complaints to the airlines in this report, for a total of 3.42 complaints per 100,000 passengers who boarded planes. Compared to the same month in 2021, complaints increased from 2.41 per 100,000 to 3.42.Experts have attributed the last year’s tumultuous flying conditions to a shortage of pilots and other airline workers, worker absenteeism driven by the continued spread of COVID-19, and extreme weather conditions.And most airlines and travel experts expect more of the same for the summer of 2022, only with 25% more expensive ticket prices compared with last year.In fact, airports this summer are anticipated to be even busier than they were pre-pandemic, in a trend experts have come to call “revenge travel.” Flyers got a taste of the busy summer travel season to come in May, which saw travel spending surge above pre-pandemic levels for the first time, according to the U.S. Travel Association.Correction: A previous version of this story had accurate data for each airline but was sorted incorrectly for the overall ranking.Continue reading for intel on which airlines you may be wise to avoid. You may also like: Most popular historic sites in America