Thank you so much for all your recommendations.finally I got the 60 days visa extension in Samui. Quite easy, didn't need TM30, only 1900 bahts and few copies and passport photo. Many people and took 4 hours (went at 9am, maybe because hokidyas of last week).
They don't ask for questions or this kind of things. So if any want the extension, here in Samui is pretty easy.
I checked with the Thai Embassy of Madrid and they told me "No, for the visa you need to get only the insurances of the list" and all are from Thailand... I'm afraid if they denies the visa.