Frontier Airlines no longer has a customer service phone line

New York (CNN) Customers who need flight information or want to make changes to travel plans can no longer call Frontier Airlines and speak to an agent, the company confirmed to CNN Saturday.

Starting last week, the ultra low-cost airline said it has transitioned to fully digital communications. Customers seeking help or information from the carrier must deal with an online chatbot, social media channels or WhatsApp. Those who need to speak to a live agent can use the carrier's 24/7 chat tool.

"We have found that most customers prefer communicating via digital channels," spokesperson Jennifer F. de la Cruz said in a statement, saying they can now receive information as "expeditiously and efficiently as possible."

Frontier is known for its cost-cutting measures, such as charging for advance seat assignments and for carry-on bags that exceed the carrier's size rules. (It checks their dimensions when you board).

Customers who call the customer service phone number now are greeted with an automated message that says, "At Frontier, we offer the lowest fares in the industry by operating our airline as efficiently as possible. We want our customers to be able to operate efficiently as well, which is why we make it easy to find what you need at Flyfrontier.com or on our mobile app. We also have a chat service available 24/7."

Its low-cost flight competitors, Spirit Airlines and Allegiant Airlines, still use call centers staffed by live agents.

It's no wonder Frontier wants to get rid of customer service over the phone. The Department of Transportation in November said it is issuing $7.25 million in fines against six airlines for the "extreme delays" in providing refunds since the start of the Covid-19 pandemic to passengers. The only US carrier was Frontier, which was fined $2.2 million by the agency.

Frontier recently launched an unlimited annual flight pass currently for $799 -- though it comes with caveats, such as blackout periods concentrated around the holidays. Customers also can't book a domestic flight more than a day in advance.

It's not the only carrier without a call center for its customers. Breeze Airways, an airline founded in 2018 by JetBlue's David Neeleman, does not even have a call center phone number. Customers are advised to contact the carrier via Facebook Messenger, text, email or they can make changes to their flights on its app and website.

-- CNN's Geneva Sands and Pete Muntean contributed to this report.