Canceling a nonrefundable ticket
Hello, I bought a nonrefundable ticket on US operated by US metal, but had to cancel due to schedule changes. I understand that what I paid for the ticket should be credited back to my account and that I should be able to use the credit for future flights that take place within one year of original travel date? If so, when I try to book a new flight that is cheaper than the original, I am still asked for payment in full... Is there something I am missing here? Do I get the credit back if I cancel a nonrefundable ticket?