Have you tried the chat function on their website below?
https://www.pontosamigo.com.br/en/como-resgatar
or at the website below?
https://www.avianca.com.br/en/web/ho...o#fale-conosco
alternative is to call the Avianca Brazil US number and asked to be transferred to the Amigo award ticketing department.
another alternative is to find a friend who speaks Portuguese! good luck.