As if the increases in flight prices aren’t frustrating enough, some airlines are charging a call center fee to buy, change, or cancel a ticket over the phone, according to Business Insider. The added costs aim to encourage customers to carry out these actions online instead of via phone in hopes of lowering phone wait times. The fees also help cover the higher costs airlines incur in keeping call centers staffed.

Though not really a new concept, many airlines that had previously done away with these fees have reinstated them, leaving customers further irritated with airlines and the chaos they have had to endure while traveling this summer.

Last week, a frustrated JetBlue customer tweeted, “JetBlue please help me. I’m trying to book online but I’m having technical difficulties. Is there a phone number I can speak to an actual person to book this flight that doesn’t cost $25?”

Allegiant currently charges a fee of $15 to buy or change a ticket on the phone with a live representative. This is on the lower end of the spectrum as far as fees go. Both United and JetBlue charge $25, and Frontier and Spirit charge a fee of $35 for each ticket.

Delta, which previously charged a phone service fee of $25, stopped charging customers to speak to an agent in 2016. Other airlines, such as Southwest, do not charge this fee at all. And although American Airlines typically charges a fee for tickets sold through its travel centers, it is now suspended and not being charged.

A spokesperson from JetBlue told Business Insider, “To keep our phone hold times as short as possible and to allow our crewmembers time to assist those customers who cannot utilize our self-service tools, JetBlue charges a $25 nonrefundable fee per-person on a reservation when you change, cancel, or complete a new booking over the phone.”

However, the airline says it is willing to waive its phone service fee for customers who attempt to change their flights online but experience technical difficulties while doing so.

Related: These U.S. Airlines Are Eliminating Change Fees for Good