No obstante, deberá pagar la diferencia de los billetes si compra un nuevo billete más caro que su tarifa anterior. En el caso de que....
https://www.linkedin.com/pulse/cuanto-cuesta-cambiar-un-vuelo-de-fecha-en-southwest-flieves/

assengers can cancel their flight according to their requirements, but they have to pay the cancelation fee that depends n their ticket, destination, and date.....
https://www.flieves.com/blogs/how-do-i-cancel-my-thai-airways-flight