Remember the days when airplane seats were large, luxurious? Flying wasn't like being stuffed into a can of sardines?

Yeah, we don't either.

A recent study sponsored by Purdue University and Wichita State University released Monday revealed that consumer complaints to the Department of Transportation grew by 20 percent last year, the Associated Press reports.

The study included airlines Air Tran, Alaska, American, American Eagle, Delta, ExpressJet, Frontier, Hawaiian, JetBlue, SkyWest, Southwest, United, US Airways and Virgin America. 

Despite the fact that airlines have been doing well in sectors such as on-time arrivals and baggage handle, the shrunken size of seats to fit more people on board has irked the masses.

United Airlines took the top spot for consumer complaint rate, with 4.24 complaints per 100,000 passengers, almost double what the airline did the year before.

A great number of overbook flights have also caused many prospective customers to be turned away; in 2012, ticket-holding passengers were turned away due to full planes at a .97 rate, compared to .78 in 2011.

According to the study, SkyWest had the largest rate of boarding denial last year amongst the 14 airlines included in the study; a whopping 2.32 per 10,000 customers.

To add insult to injury, airlines are considering making those tiny bathrooms even smaller, in efforts to fill planes with that many more seats.

"The way airlines have taken 130-seat airplanes and expanded them to 150 seats to squeeze out more revenue I think is finally catching up with them," Dean Headley, business professor at Wichita State, told the AP. "People are saying, 'Look, I don't fit here. Do something about this.' At some point airlines can't keep shrinking seats to put more people in the same tube."