An update on my saga...

Called the US 800 number today and was told again "no refunds, only vouchers"
Called my credit card (Chase) and was told 1+ hour wait time for the disputes office
Decided to call the Spain number via Skype and - after 30 minutes on hold, but with no argument - the agent said he entered the refund request for processing.
Estimated processing time was 3-4 weeks, so probably not finished with this adventure - and unfortunately, another ticket in May that will probably be cancelled.