Thanks Pedro for sending me the link to yesterday's BOC. It seems now that our dear rulemakers have decided to (once and for all) call a spade a spade (if you know what I mean). Up until just a few days the official term for the title was "acreditación". Oddly enough, I have just noticed that the latest version of the "Guía del Candidato" (not the one available on Educantabria, which is dated) consistently makes use of the expression "certificación" when it refers to the C1 exam, as does the aforementioned BOC. On page 3 of yesterday's issue we can actually read the following :

La posesión del Certificado del Nivel C1 acredita una competencia de idioma del nivel C1 del Consejo de Europa. 

All I can say is... this has been a rather convoluted affair. There has been a number of unclear and even contradictory message. I trust the matter has been officially settled. It appears you guys are going to have the chance to obtain a real certificate. So be it! As far as I'm aware, though, you will have to register for the exam and pay the fees (all of you except for Puerto). Good luck!