http://ec.europa.eu/transport/passen...ent_bodies.pdf
Scan down this document and you will find the address and contact details for the "competant authority" in Portugal. Complete the application form, you can find here...
http://ec.europa.eu/transport/passengers/air/air_en.htm
This also provides more detail, which you seem to know, that the EU does not accept mechanical breakdown as "extraordinary". The airlines are engaged in a war of attrition with passengers and the EU to try and get this regulation modified. We need informed passengers like you to persist.
If you get the national competent agency in Portugal to support your case, you can file in small claims and get a judgement against them on the back of this.
I hope you will persist....