According to Turkish Airlines cancellation policy, you are free to reschedule your trip at no additional cost if the airline cancels it for unavoidable reasons such as a loss of control, a technical error, or other particular causes. You can get a refund if you buy your ticket straight from turkishairlines.com in the event that you need to cancel. Turkish Airlines cancellation policy is that you will only be refunded taxes if you need to cancel a non-refundable ticket. You can ask for a refund if the airline rescheduled your travel and the new reservation does not suit your needs.
https://flightcancellationpoli....cy.com/turkish-airli

If you purchase a plane ticket for travel to or from the US and decide to cancel within one day after purchasing, no cancellation costs will be subtracted from your refund by Eva Airlines. Only those who have refundable tickets are eligible for a complete refund, per the Eva’s Airlines Cancellation policy. On the other hand, non-refundable ticket holders will be responsible for cancellation fees.
https://flightcancellationpoli....cy.com/eva-air-cance

When changing a flight, the customer must follow certain flight change policies and getting information about these policies is essential because it will let you know whether you have to pay a change fee or not. If you don't know about Avianca flight change policy, please review below.
https://flightcancellationpoli....cy.com/avianca-chang