Just a heads-up....
I normally see my GAME reward card total when I log onto the GAME website, and I noticed that although I had recently bought something from their store, my points didn't seem to have updated.
Well, I contacted them via their website, and asked them to send me a list of all the transactions on there, and lo-and-behold, when I had traded some games in, they had deducted the points value from my Reward Points!
For example, I traded World Championship Snooker '07 on the PS3 in, getting £15.60 store credit, and unbeknowns to me, they then deducted 156 points from my Reward Card!
So, if you think you have some missing points, you might wanna do the same... IF you can be bothered ;-)