Xbox 360 can't download DLC

I've recently bought the Mass Effect trilogy pack, and I loved it so much I decided to get all the story DLC. I had no problem purchasing it for the first game and the third seemed to work too, but I cannot  buy anything for the second, I can't even get the DLCs that are free for me on the Cerberus network. I got a Cerberus network key, my copy is not preowned, and I'm able to access the network (well most of the time, for a while it would not connect). When I bring up the Cerberus network it shows all available content, but when I select it I simply get an error message saying: Item is not available. What gives?

Why can't I download anything not even the DLCs I'm supposed to get for free?

Is it a regional thing (I live in Hungary), and if it is how can I solve it without moving to a not discriminated region?

Can region settings on xbox live sort this out?

I just don't get, why I can buy the content for the other two games but not for this?