Is a coffee a coffee by any other name?

I live in Catalonia. My partner identifies himself as Catalan, as does his parents and most of his friends. My child goes to a school where all the teaching, apart from language classes are in Catalan. And yet, I can't order a café amb llet without the waiter/waitress 'correcting' my poorly accented Catalan into Spanish. Today, the woman asked me three times what I wanted, then I thought she was going to make me repeat café con leche with her, just as a special favour.