Long lines, stranded passengers and more than half of flights canceled as Spirit Airlines enters fifth day of "operational issues"

Spirit Airlines is struggling to rebound as it enters its fifth day of widespread cancellations. By Thursday evening, Spirit had canceled 55% of the day's scheduled flights, according to global aviation database, FlightAware. 

Spirit spokesperson, Erik Hofmeyer, attributed the widespread delays and cancellations to "operational issues," including staffing shortages, severe weather and system outages that began Sunday. Spirit is offering to double its pay for flight attendants to work extra shifts.

Hofmeyer, along with the airline's pilot and flight attendant union, have debunked rumors that claim the travel issues stem from a pilot strike. "It's completely untrue," Hofmeyer said. 

He said Wednesday that a network reboot would help to "progressively drop" cancellations in the coming days and that lines had "decreased substantially." But on Thursday, more than 430 flights had been canceled. 

Spirt told CBS News on Thursday that cancellations will continue throughout the week and weekend, but that they will decrease. They said the main issue currently is crew scheduling and that there is a plan in place. 

Dallas resident Kai Scates told CBS News that Spirit's issues turned her weekend trip into a four-day "nightmare." She said five flights were canceled while trying to fly home from New York with Spirit Airlines on Sunday.

"We boarded the plane and we're just kind of sitting on the plane for about 25 minutes and then one of the stewardesses stood up and told us that our flight was canceled," Scates said of one of her flights with Spirit. "So I got off the plane, went downstairs to rebook and it was hundreds of people trying to get in line because their flights had been canceled too."

Between sleeping in the airport and traveling through three different cities, Scates said she returned home late Wednesday night, missing days of work. "I couldn't get on the phone with anybody, can't get anybody to respond," she said. "It was crazy."

Spirit Airlines said Wednesday that they "sincerely apologize" for the widespread outages and that the airline is working to provide refunds for cancelled flights and re-accommodate guests when possible.

The airline's flight attendant union said it had a call with the pilots union and the company's CEO and chief operating officer.

"We sincerely regret the inconvenience this has caused," Hofmeyer said, mentioning that crews are "working around the clock to mitigate the travel disruptions."

He asked Spirit passengers to check for flight status notifications on their website before going to the airport.