My Reward points never showed up and the site has no info about them.

Credits are deposited by the following 15th or 30th of the month after you have at least 5,000 pending. Generally, if you get to 5,000 between the 1st and 15th, they are deposited by the 30th. If you get to 5,000 between the 15th and 30th, they are deposited
by the 15th of the next month. So if you got to 5,000 early this month, they would be scheduled for the end of the month deposit which is scheduled for the 22nd.

Actually I am, and I keep up on that. But nothing came from there. Weirdly enough, the points were taken away. My Microsoft site account info still doesn't show what happened. Which now really worries me, because now someone has the power to take away my
points that I actually paid for or earned through rewards? :-/

The credits should show as pending on the MyRewards section of the Rewards site about 96 hours after you redeemed them.

The 3,428 points you're referring to are from the Microsoft Rewards program, not the Xbox Rewards program. Those are separate.

There's a breakdown of your points on the reward site. First tab is points awarded, those should all show a date that tells you when they were deposited. Pending points will accumulate until you get to 100+, then they are awarded on the 15th or 30th of the
month. If you go here http://rewards.xbox.com/faq/ and click on My Rewards, there's some great info under the Rewards section.

Rewards credits are not emailed. They show as pending on the rewards site about 96 hours after you redeem them.