The codes I just got, two of them are region locked. I am in Canada

That would indicate that your Xbox Live account region is not set to the region you're physically located in. To address this, please use the
Xbox Live Account Region Migration tool. Let us know how it goes!

[quote user="xTetsiagax"]i got some points from the US and im in Canada, so i cant redeem it so i had another account redeem them but i still cant download map packs[/quote]

That's a two-part problem:

1. Microsoft Points are region-locked; you can't put U.S. Points on a Canadian account.
   
2. Many DLC map packs are now region locked. It sounds like you created a U.S. account to apply the U.S. points, but then ran into a different region lock: a U.S. account can't download and use region-locked map packs while located on a console in Canada
   (or any other country). You should be able to use the Points on other content, though, and share it with the other profiles on your console (except for Avatar Marketplace items), because not all stuff is region locked.
   

Microsoft system is just too heavy on its own, it could hardly float.

I am sure this is related to Region Lock problem either because the buyer is in a blocked region, or has a bad IP Address that MS is not able to identify the region. Or perhaps MS records got screwed, they thought you are from Mars mimicking a Canada IP....

MS Should simplify this XBOXLive, remove all those crap "Region Lock" and just allow everyone to buy whatever games they want wherever they are.

another possibility of to why it says invalid is if your regions don't match (you are in say canada and you got the 360 with the codes in usa) if that is the case it may give you that error as some games are region locked. if you are both in the same region
than all I can suggest is calling support for your region good luck.

The codes are not region locked so replacement codes would give the same errors. The games are region locked, so in order to download them, your account region has to match your physical location and you have to live in a region where the games are available

I registered and physically I was in Russia, and these two codes, as I understand it for the United States, what should I do?)