If you want to complain about Portuguese state-mafia: https://www.cada.pt/ . The police should have responded in 20 days, see art 16 of https://www.parlamento.pt/sites/EN/Parliament/Documents/Lei26_2016.en.pdf . 

Another idea: habeas corpus, any Portuguese citizen can file it, art. 31 of Portuguese constitution, see https://en.wikisource.org/wiki/Translation:Constitution_of_the_Portuguese_Republic_(1976)#TITLE_II_Rights,_liberties_and_guarantees . But this could be seen as abuse, they surely have perfect justification for the detention, they just don't feel like providing info. And petitioner can be fined for "manifestly unfounded" habeas corpus petition.

I suspect they have no obligation to communicate in English. If I was Portuguese police and wanted to withhold info with some plausibly-sounding justification, the language would be my first excuse.