When it comes to air travel, some hiccups, like weather-related flight delays and the occasional lost bags, are unavoidable. But one factor that is within an airline's control is their customer service. What makes the difference between a positive experience and a negative one usually isn't how long you waited on the tarmac or whether the in-flight headphones worked, but how you were treated. Good customer service can go miles toward making a passenger feel welcomed or smoothing over a difficult situation. But unfortunately, not every airline is able to pull this off with aplomb: the 10 airlines listed here ranked last in customer service in this year's World's Best Awards survey.

From the moment a passenger clicks onto an airline's website to the second they retrieve their last piece of luggage from baggage claim and make their way to the airport exit, there are so many opportunities for a brand to get their customer interface right - and perhaps even more ways they can screw it up, as the 2015 T+L survey responses highlighted. For more on the methodology of our survey, click here.

Several readers noted that a clunky website can be maddening, especially when coupled with inadequate phone support, as is a hectic boarding system. Other T+L readers complained about shoddy loyalty programs that inspired, well, disloyalty, with fewer benefits and expanded restrictions that make it difficult to use frequent flyer miles. But the subject that prompted the most rancor was unfriendly or disinterested airline representatives and flight attendants. "Poorly trained staff," wrote one survey respondent about Spirit Airlines, which received the dubious distinction of being the number one worst airline for customer service. "Unprofessional and not helpful on the plane flight."

Disgruntled tweets, frustrated Facebook messages, detailed critiques on travel review websites like SkyTrax, and official complaints registered with the Department of Transportation in a public report help complete the picture now that social media is making it easier than ever for travelers to voice their concerns. Some users craft concise complaints in 140 characters or less on Twitter, while others document their displeasure with tell-all Instagrams. "Hey @AmericanAir," said Instagram user @UpgradeToFirst, who posted an unappetizing photo of an inflight meal. "Is this the best you can do? The taco salad is absolutely gross."

With critiques that range from the heartbreaking to the utterly outrageous, here's what T+L readers and other travelers had to say about customer service on the 10 airlines that came in at the bottom of pile.