"...and probably non-existent now, so a replacement is probably not an option."

It might a good idea not to assume failure at the outset. What harm is there in taking the bike to the local shop as Specialized suggests? You certainly won't get any warranty satisfaction if you do not begin the claims process.

If you were sold a returned frame as new and can make a persuasive case of this they might just possibly be able to come up with a replacement rather than risk a fraud accusation.