Kinda had myself worried when I got the redemption error as well, but now that it seems it's occurring over multiple accounts it's probably more than likely a glitch in their redemption system. By all rights the errors should be resolved by tomorrow if it isnt an account closure.

Edit: For those wondering, and getting the error, it seems that whatever was going on to cause them is resolved as I just made a redemption for a 100MS point code. I wasnt able to earlier, but just now had a successful redemption. So it doesnt seem like MS went on a banning spree or nothing. Just a glitch in the system.