LATAM Airlines / LAN Airlines review: rude and not well informed agent

I was traveling back to United States with my daughter who is American and the agent lady said I needed to proof I was her mother, and did not want to give me my boarding pass. I told her many times it was a Brazilian law for Brazilian kids to have authorization and information of the parents, and once a child was American, , the child had the right to go back to her country, and she insisted I needed to proof I was her mother, she said she talked with the supervisor and I was supposed to go on second floor for talk to the federal police. I talked to them and they said there was no problem of my daughter to go back to US. But as always been in Brazil one throws the problem to the other. The police said maybe it was a Latam company policy and to try to talk to them again, I went directly to the supervisor Paulo, who was extremely nice and he said I was right, he stayed with me the whole time until I got my ticket, and said the agent lady probably talked with somebody else and not him. She was very rude to me, and not even tried to give me a chance to understand and she said:" I don't know from where are you getting all these information " when I said many times it was the law, which she did not know