Me and all my friends from Brazil are being placed in NA server when we play solo mode. There are enough players for a decent match in SA servers, and we all agree that is better to play in a 30~40 players lobby with good ping than play in 100 players lobby with 150~200 ping. Please, fix your matchmaking, we are just about to give up from the game because the experience of play HS with high latency is terrible.
I'm sorry to hear that you are experiencing this, I will report it to the dev team.
In the meantime could you please try manually configuring your data centre by checking the support article here.