[PCEARTH]

I intended to fly from Montevideo, Uruguay to Japan, via Sao Paulo, Brazil. I first bought two tickets from Etihad for a trip from Sao Paolo to Japan. Then I purchased two tickets from GOL ailines (Brazil) from Montevideo to Sao Paulo.
I was informed by Etihad that as I would not have to leave the international airline terminal we, a Canadian and a Japanese, would not need an entry visa for Brazil as we would did not need to leave the International lounge which both airlines operate out of.
Then when we arrived at the GOL check in desk at Montevideo we were not allowed to board, because we did not have a visa to enter Brazil and this wa because, and I quote the airline superintendent of security, 'GOL cannot trust it's passengers not to enter Brazil' and 'GOL could get fined for bringing a passenger without a visa'.
This caused us to loose thousands of dollars worth of tickets.
Both airlines have denied responsibility.
GOL are just out and out unhelpful, ETIHAD claim that 'of curse all airlines have different policies'.
I would have thought that the laws of immigration at Sao Paulo airport would be the same for all people, whichever airline they fly into.
Please can anyone explain to me how this can be and what if anything I can do about it?