It may also depend upon who issued the tickets - an agency or UAL themselves? You can only return to the company from whom you purchased them.
If you are going to attempt to get your money back, you had better have a genuine letter from the (putative) bride and groom, explaining about the cancellation, appologising and so forth. It may also hinge on whether the folks getting married were CLOSE family or simply friends.
Given the downturn in the market, I have to agree that your chances of a refund are slight. Which reminds me, I am going to a long-haul wedding in December!