door salesmen

I just had a young man at my door reporting to work for nos, he showed me an id on his tablet and asked for my fiscal number to upgrade to fiber (as it has only just been launched in area) I gave him my nif, he then had all my contract details and was pushing for mtme to sign and give him my identification, which I refused, he then became rude and angry that I would not let him in or give my passport for identity. I would like to know if this guy was actually legit working for nos. It was a bank holiday today and was at around 6pm he cane to my door. In albufeira e olhos de água, Algarve