Well, I tried contacting the local support before. I contacted them in early November through phone contact. They told me to ask for help on their online chat, the chat then told me to email them...
Once I sent the email, it took them 8 days to reply, with mostly useless information, it seemed like they didn't even read my email. After over a month of useless chatting with them (they don't even seem to know what signal to noise rating is), I asked for a refund and that I would send them the device. They denied it and told me to go on store that handles technical dificulties in DLink hardware in my region.
I went twice. The first time there were no technicians and only the phone lady was there. The second time, they opened up the device and said "well, it should work". Tried setting up a local network through it and it failed as it failed in my house. They said that it was problem on their internet provider and that it happens with any device, and that it should work on my house. The thing is, they tried to charge me R$ 150,00 for assistance (which is around 50-60 USD).
So yeah... DLink costumer service is pretty incompetent in my country. I feel like a have no options other than getting another model and dealing with the cost of this malfunctioning product.