I do had a similar issue once and I am afraid the money you've lost (I assume you only received taxes back) is really gone. Please give it a try, but I had a large number of Business flights with them at that time, and was already a status customer, but my reply was 'sorry, no chance'.

It is interesting though that, despite of the lack of general customer protection close to EU/UK 261, US airlines give out travel vouchers when cancelling a flight.