As above. But didn't you wonder where the points had come from? I had the same issue, saw my points jump up and I instantly knew something was wrong. They have taken back all points now that were issued incorrectly.
It was a glitch in the rewards system. Albeit being a mistake, they were your points. The official xbox support twitter page confirmed that. But knowing Microsoft, they changed their minds and took them back already after ensuring users that the points are
theirs. I knew I shouldn't have trusted Microsoft with anything free. I didn't spend the points on time because of Microsofts statement.