Ok, so my wife and myself bought NWA round trip tickets LGA-SNA-LGA for vacation.

She later found out that she had to attend a conference somewhere in Illinois while we were supposed to fly the LGA-SNA part.

Fees to change the tickets to change the ticket into an illinois-SNA-LGA ticket: $500

Price to buy a plane ticket illinois-SNA on another airline: $150

We don't worry about LGA-illinois since it's gonna be paid by the conference.

The ticket is non-refundable.

Option 1: Not fly the LGA-SNA leg and buy a ticket on another airline: Can comebody confirm (or infirm) that failure to fly the first leg will cause NWA to cancel the full ticket?

Option 2: Pay the $500 (we obviously want to avoid that).

Option 3: Cancel the full NWA ticket and buy the round trip on another airline. If we do that, while we will not get a $$$refund, could somebody tell us if we would get a credit voucher to use toward another NWA ticket (minus fee, how much)?

PS: the ticket was originnally bought with credit voucher issued following luggage delays.

Thank you very much.